I haven't seen anyone get squashed for voicing a dissenting opinion.
I have seen people asked to back up their opinion - especially if it doesn't jibe with conventional wisdom. That's how paradigms get changed and we all learn something.
What I have seen is people getting squashed for being rude or belligerent while voicing their opinions. And in those cases, the squashing was for the method chosen to deliver the opinion, not the opinion itself.
It is entirely possible to voice a contrary opinion to the masses or post a negative concerning PRS without resulting to ad hominen attacks.
As far as cliques go - some people know some people better than they do others. Some people like some people better than they do others. That's life. Nothing artificial here about that. That being said, I'm not sure if I sit at the cool table or not. It's OK if I do. It's also OK if I don't.