Well, it depends. Sometimes people act like ass hats in a sarcastic manner, sometimes they do it when they're in a bad mood, but a lot of the time it can't really be explained. But if you come across them, remember: "Ignorance Is Bliss".
Ah, the Fursuit forums. Nothing much of interest happens 'round there, from what I can tell. The general concensus around here is that The Den is where most of the drama takes place; i'd steer clear of dramatic activity unless you wish to make fun of it, as I do. You know what's really interesting, though? Threads in the Art Exchange where people complain about certain users "leeching art off people" and ganging up on them. They exhibit a strange sense of community spirit that you don't find anywhere else.