I don't think a forum could be this successful if it was really hostile to the members. This is an incredibly popular forum and I certainly don't consider it unfriendly at all--and I have been to some pretty hostile ones.
I think many of the problematic posts come from answering the same question several times in a relatively short time. Often times people choose to start a new thread rather than search, and this can cause a lot of frustration for the people that answer the same question multiple times. Searching will often find the answers faster than starting a new thread and waiting for answers.
This place is tame. I go here: http://www.imdb.com/board/bd0000044/threads/?c=1 when I've had enough of heavy moderation and feel like verbally punishing some people with no consequences. Say what I say there on here and I'd be banned immediately.