Regrettably, I probably inadvertently helped with this culture as I also started the Administrators' notice board. Never have I seen such a cesspool of controversy, beaurocracy, wiki-lawyering and frankly power hungry people. I suffer from bouts of depression, so have left and returned a few times (actually I was made admin three times), but the last time (and believe me, the very last time) I tried to contribute I noticed the complete and utter lack of civility in the place. In a naive attempt to address this I tried to propose a policy where civility would be encouraged and incivility would be discouraged.
One of the key opponents, a user called Giano, went on the attack and I left the site - especially after I was told via email from Brad Fitzpatrick that I was unwelcome on Wikipedia.
I thought to myself: "I spent 2 years researching and writing about the USA PATRIOT Act for this?!?" 
And I left and never came back.
But, hey, if you want to see the discouragement that an average user sees - checkout my old user page. Even though it is a user page that very clearly says I have "retired" (more like sacked) there is wall to wall templates telling me I have committed a copyright violation (like hell!), or that images or articles will be deleted, etc. 
Further to this: deletionism is a massive problem. If you don't believe me, look at the GNAA article - there were 17 different attempts to delete it!  Of course, Jimbo Wales supported the deletion for fairly spurious reasons in 2006.  I await the day that my article Exploding Whales is deleted.
Note that I did this because of the following article:
Reddit sort of avoids this because it's so easy to create new subreddits that people can vote with their feet if a moderator is behaving unreasonably. Maybe a similar solution could work for Wikipedia, having sub-Wikipedias with different rules. But that would require the current powers to admit that there's a problem, which is unlikely to happen.
>The human longing for freedom of information is a terrible and wonderful thing. It delineates a pivotal difference between mental emancipation and slavery. It has launched protests, rebellions, and revolutions. Thousands have devoted their lives to it, thousands of others have even died for it. And it can be stopped dead in its tracks by requiring people to search for “how to set up proxy” before viewing their anti-government website.
Basically: if you wanted to discuss a vague subject that doesn't have a limited set of possible answers, you should probably use a discussion board instead of using a stackexchange website. That's part of the reason why Jeff Atwood left to create Discourse.
Obviously Slashdot is a bit different since the content is moderated, not voted up or user-created. However, the idea of having "catch-all" rules that allow the community to apply its own value judgements, rather than making the rules ironclad and inflexible, seems like a potential solution to the problem.
I consider it analogous to the SciFi channel showing professional wrestling, or MTV showing reality TV, or the gradual slide of TLC and History channel into slop. Niche media is destroyed by pejoration toward the mainstream.
Also, I didn't mean to imply that the site creators intended for the motto to be applied in the way I described, just that it was applied that way in many cases.
The point is that sometimes making the rules a little fuzzy can allow a community to moderate itself more flexibly and prevent the "lawyers" from taking over. HN is similar, where though there are loose guidelines, the rules for appropriate content are (deliberately, I believe) kept vague.
Ie, don't just delete/close my question - give me somewhere else I can ask it - or even migrate it - preferably to another stackexchange site. It's probably why stack sites like Programmers were created.
That would defray most of the downsides of "strict rules" based rejections.
No single website can reasonably hope to cater to everyone's interests but luckily the web makes it very easy to create alternatives.
For the other points that I mentioned, I'm not sure I know many wiki hosts which are free as in free beer, run by a nonprofit, sustainable through donations, show no ads, have their content under a free license and dump it in a way comparable to http://dumps.wikimedia.org/.
> No single website can reasonably hope to cater to everyone's interests
Should there be pictures of Mohammed on the website? Yes or no?
Should homosexuality be mentioned at all? Yes or no?
Does homeopathy work? Yes or no?
Some issues have no middle ground, or at least no factually-supported middle ground. Therefore, to even address some topics, you have to take a stand, which necessarily means you alienate some people.
In some cases I think the real fix is outside Wikipedia: if "the literature" (books, magazines, newspapers, journals, other encyclopedias, etc.) have not yet covered a subject, the first order of business is to fix that gap. But I don't think Wikipedia is the right place to go about fixing it. IMO Wikipedia makes most sense with somewhat limited ambition: to summarize the existing literature, with references. That's already a pretty large endeavor, especially when you include summarizing the existing literature globally and multilingually. When the existing literature itself is lacking, I think that should also be fixed, but not by Wikipedia.
Once the problem is fixed in "the literature", it's then much easier to fix it in Wikipedia. For example I sometimes look at the MIT Press new-books list, or the Stanford Encyclopedia of Philosophy new-articles list, and write at least short new Wikipedia articles on subjects that they cover which Wikipedia doesn't yet cover. For me at least, that "source-first" subject selection tends to be the most relaxing way to write on Wikipedia: instead of picking a subject you want to cover and then finding sources, find good sources and ask, "what do these cover that Wikipedia doesn't?". That way of working has a good impedance match to Wikipedia's goal of being a sources-cited summary of the existing literature.
I wrote something more long-winded on that subject a bit ago: http://www.kmjn.org/notes/wikipedia_notability_verifiability...
But, the people making the decisions are occasionally just ornery. I seem to recall trying to straighten out some errors about Open Source stuff I work on, and having it reverted and moved around, sometimes in ways that simply made things confusing (removing pages and redirecting to related but different projects), etc. It's been years, but it was frustrating, and I just kinda gave up. I don't have an interest in territorial battles.
I might give it another shot some time. I've switched our documentation wiki for Webmin to MediaWiki a few weeks ago, so I'm back up to speed on MediaWiki markup, so that's less of a barrier for me these days (never was a huge barrier, except for a few of the special stuff, like info boxes and automatically updating stuff). I'd be interested to see if these complaints have been taken to heart by folks involved...it's a drum that's been beaten for some time by a variety of long-time contributors.
I never realized things had got so bad on wikipedia.
I tried it and mostly got vanity pages for people who did something, but didn't seem too important.
One I got is about the mayor from 1995 to 2001 of a Texas town of 75,000 people. I suppose it has some value to the people who lived in that town or need to research about it... but I can sympathize with the problem of trying to decide what is useful and what is not.
Another one is an article on the Tigress character in Kung-Fu Panda. I mean, sure, it was information, but the extent of its vitality to human knowledge and literature?
Another one is a 7th round hockey player from Canada...
I mean, should Wikipedia really keep track of all athletes, all mayors, and all characters in all movies?
I think it's a better idea to keep track of more permanent stuff and let fans of these athletes, mayors and cartoon characters make websites about them.
I tend to agree that there's a bunch of stuff in Wikipedia that's pointless. But so what? How much does it cost Wikipedia to host the Tigress from Kung-Fu Panda page?
"The subsequent research has in some respects vindicated my views: some have tried to argue that the declines are due to picking all the low-hanging fruit in articles or in available editors, that lower quality editors merited additional procedures."
The weekly list of the 5,000 most viewed pages on Wikipedia (which includes one page that I improved from a frequently edit-warred stub to a stable good article by adding dozens of references to reliable sources to it) shows what users are often looking for on Wikipedia. Some topics are seasonal, and others are perennial. Many Wikipedians could best help the world by fixing one of the perennial highly viewed articles until it is a good article or a featured article.
Basis of knowledge: I have been a Wikipedian since 2010. I have seen a lot of readers get burned by articles edited on the principle of "Wikipedia is the encyclopedia where anyone can make stuff up.™" Articles become better and edit wars are reduced when people come to the project with reliable sources to build an encyclopedia.
'a group is its own worst enemy'. If you only started in 2010, then the disaster is just the status quo to you.
Well, yes a group that whines continually about what Wikipedia doesn't host without putting up its own online encyclopedia showing what could be hosted under different editorial policies is indeed the worst enemy of its own arguments for having different editorial policies in an online encyclopedia. Show, don't tell.
By the way, a search engine search on the Clay Shirky quotation you shared without attribution suggests by its top search result that the problem of spam in online communities is ongoing. Jeff Atwood recommends Shirky's article "Communities, Audiences, and Scale" from 6 April 2002 as a follow-up to the article where Shirky introduced the phrase you quoted. As Shirky notes, "Though it is tempting to think that we can somehow do away with the effects of mass media with new technology, the difficulty of reaching millions or even tens of thousands of people one community at a time is as much about human wiring as it is about network wiring. No matter how community minded a media outlet is, needing to reach a large group of people creates asymmetry and disconnection among that group -- turns them into an audience, in other words -- and there is no easy technological fix for that problem."
If Wikipedia is being rude and alienating users, then people will leave. Eventually something else will come along and take their place.
Of course Wikipedia editorship is declining. Most of the important articles were written years ago. Encyclopedias, over time, move to maintenance mode, which requires far less work than original creation.
There's also a growing self-promotion problem. Self-promotion used to be mostly from garage bands. Now, it's businessmen. There are at least four rich ex-cons with paid Wikipedia editors. Businesses trying to make some big legal mess disappear are the worst. Magnetix and Banc De Binary were huge headaches. Volunteers have to push back against that, or Wikipedia becomes PR Newswire.
That's not remotely accurate. The problems are across all subject areas; consider my link deletion experiments.
The entire Internet is going this way. I overestimated its inherent resistance to gaming/doctoring.
For example, product reviews are increasingly unreliable. Even on platforms that require purchase, like Amazon. Meanwhile specialist sites like tomshardware and anandtech seem overwhelmed.
Spamming social to get higher search rankings is easy, cheap, and hurts both search and social, as blogs, forums, and discussions fill up with promotional crap no one wants to read. I work on web spam and bogus ad detection, which means I'm painfully aware of the ocean of promotional crap out there. I'd like to see Wikipedia not go that way.