so because google's algos can not distinguish between spam and ham, we have to throw out the baby with the bathwater (sorry for mixing metaphors!)
we've already seen how google missed a massive and long running link scheme (rapgenius) and had to do a clumsy temporary manual change to save face... now we're seeing them try to stop guest blogging from being used for spam
well guess what, every tactic that can be used to create good SEO can be used in the wrong hands for 'bad' SEO. you can leave a great insightful comment or you can leave a spammy comment. you can do a great guest blog article which adds tremendous value or you can do a spammy terrible article
google is confessing that they are incapable of telling them apart so they want to destroy the whole thing just so they can go on saying that they still know what they are doing
well, let me reiterate what many already know: the emperor has no clothes!
You need links as well. "Sure, but good content will naturally be linked to", but then ask yourself, when was the last time you gave something you liked a dofollow link on your blog? And even if you did, you maybe gave one link for every 100 you enjoyed but didn't.
People very rarely link to things these days, and the big guys will pay people to provide links. Guest blogging was previously the ethical way to get those links until people started abusing it.
If the difference between dofollow and nofollow links is outcome determinative over whether or not some article would be written or posted, then it is SEO crap and it should be ignored at best by search engines.
And if it's not outcome determinative, just put nofollow on the links and you don't have anything to worry about.
I use markdown for my blog, which is then compiled by Jekyll. Why should I know or care what a nofollow link is? I link to things so that my readers can click on the link and read more about whatever I'm saying.
It's my job to act naturally and not try to game the system. It's Google's job to figure out whether I'm acting normally or gaming the system.
That's a legitimate concern, but it has a narrower application than you've suggested. If a blog post doesn't have links that point back to the author's "home" website, then it's not an issue either way. Also, either the author or the guest site can set nofollow.
So our hypothetical innocent user has to be sophisticated enough to 1) have a home site, 2) blog on a different site, and 3) include links, (and have some legitimate non-SEO reason to want to put links to his home page in the first place) while at the same time neither he nor his host be sophisticated enough to know about nofollow.
It's certainly possible but I'm skeptical that it is a large catagory. Plus, I doubt that whatever countermeasure google comes up with is going to be a nuke from orbit response for a very occasional suspected spammy guest post. Instead I expect they will be going after the many many instances that look like a concerted effort.
I must admit that I'm not blogging myself at the moment, so I haven't really thought about these things before now.
My assumption is that a non-technical person would go with some key-in-hand automatically configured solution. So to be on the safe side, any ready-to-use blog hoster should, by default, set all links to be nofollow links, right? Because you really _have_ to know about nofollow if you want to use it only some of the time.
Also, a non-technical person, upon being told that they can't link to their own site and probably also to the sites of other authors on the blog, might not be inclined to see this as anything but some arbitrary rule.
All is probably lost, anyway. This just speeds up the exodus of non-technical bloggers into the walled gardens that lure them.
Well if someone's hosting guest posts on their blog for non-SEO purposes it's generally because the think the guest blogger's writing is good and that their regular readers would be interested in seeing it.
From what I've seen, it's more or less the norm that guest posters have a blog elsewhere that's linked to in the post; if they didn't have one the host would have no way to assess the quality of their posts, and reputable blogs don't accept guest posts from people whose blogs they're not comfortable promoting to their readers.