I'm not aware of the Tier 1, holier than thou bunch. I suppose that makes my opinion invalid. I'll offer it anyway.
As far as freedom of speech, we certainly wouldn't say that means all speech is of equal value. Just because I believe you have the right or opportunity to speak your mind doesn't mean you are saying anything of value. Just look at GSF if you need proof.
Surely there is some value in most things posted. But obviously some posts have more value than others. But everybody, with the possible exception of GSF, posts stuff that they think they know to be the best. They are offering the best that they know. Well, you certainly cant expect them to react well when someone comes along and says something that is different. Different is not equal. So if one guy says one thing, and another guy says another thing, then they obviously are going to think the other is an idiot.
So if some idiot comes along and posts something after me, he's basically calling me an idiot to my face right? If I say you should mow with a riding mower, and he says that riding mowers tear up the grass, he's basically saying I'm trying to set you up for failure. How should I react to that? I'm certainly not going to be happy about it. So, if I'm feeling good, I'm going to defend my claim; and if I'm feeling shitty, I'm going to just criticize his claim, but either way, it's not likely to be received well.
What I'm getting at is that it's human nature to defend yourself against perceived attack, and that posting something that is different than what somebody else posted will be perceived as an attack. Chances are though, that someone is right and someone is wrong. The person that is wrong, might even know he's wrong, but admitting it isn't really human nature. That person who is wrong will try to attack the other folks, but in the end, he'll still be wrong.
I suspect that if you looked at any of the threads where you perceived this dog-piling going on, you will probably see that the guy getting attacked probably did offer substandard advice, and probably had an opportunity to admit it, but chose not to. If that thread has me getting attacked, I guarantee you that's what happened.
ETA: Going back and reading Council of Dave's post makes me realize I should point out that I'm talking about opinions.