To be honest, I don't even know which comm you're referring to, but I doubt it matters much. I think you're right: I think a lot of people do hate the fans, on both sides of the aisle. (Hell, some days, I hate the fans, and I'm reasonably neutral!)

That said, while I DO think fandom in general would be much nicer if more people respected each others' opinions, I will say that I feel as though comms devoted to one pairing over another kind of have a right to "bash" the other pairings; it's just that, by doing that, rather than just ignoring the other pairings (well, at least as much as possible; sometimes it IS a matter of "us" versus "them"), they--IMHO--come across as douches on occasion.