There's a whole spectrum of ways to disagree, all of which have value in the right situation. Here, a good portion of that spectrum has been lobbed off in the name of niceness and nothing more. Is it worth it? Decide for yourself. I say nay.
Bonus disease: PG worship. Don't get me wrong, he's a brilliant guy; we're all here (directly or indirectly) because of him. But it goes too far.
On the topic of "PG worship" I think, yes, perhaps the constant extolment goes a little to far. I think this is a blindspot of HN simply because most of us are pretty polite. One doesn't go into a host's house and take a dump on the floor, if I may. Sometimes I feel it may be rude to criticize Paul in this forum for a similar reason.
Criticism is not impolite. In fact, it's the direct opposite. Criticism is a show of respect. You criticize someone when you care about them, when you desire their betterment and you respect them enough to be confident that they will not react negatively to the idea that someone else may know better than they do.
I preferred to absent myself from here for a while after it got real bad (to the point of the first article commonly being a 2-3 year old essay that had bubbled to the top AGAIN), simply because I felt fundamentally outside of the norm here - I rarely agree with anything PG says in its entirety. Paul is a thoughtful enough person that I've never felt that it would upset him if I disagreed here, but I would imagine there would be a lot of people keen to argue with me until I was blue in the face about it.
An opinion is an opinion however, and we're all entitled to our own - I take downvotes not as a personal attack, but simply an expression of disagreement, be it with your opinion OR the way you express it.
I tend to upvote anything that seems coherent and interesting, not just the stuff I agree with. If I ever get to the point where I'm allowed to downvote, I'll exercise that privilege only to mod down trolls, spammers, or very bad style. Everything else can much better be handled by replying to an entry and having an actual discussion.
So am I mistaken? What is the mod system for, officially? Quality control or consensus building?
This leads to cases where coherent and interesting comments are sometimes -4, which is exactly the rating that should be reserved for porn, spam and really gross trolling. At the same time, some users achieve consistently high ratings for comments that seem to be lacking in content, leading me as a new user to suspect that the system is either rigged in some way or at least very susceptible to ridiculous pile-on effects.
The good news is though that this doesn't happen often enough to be a serious problem (yet?).