Battlegrounds? No problem. I'm not sure why. The language and verbal attacks are often much worse there, and I know that's why many people stay away. But I guess it's more impersonal there and much more common. Maybe that's why I can handle it so easily.
It is definitely much more personal in a 5-man group. That's certain. It's not "you all suck," but "you suck, Laurel." If I'm really not doing well, there are better ways to tell me, obviously. More often, however, the blamer is the one with the problem. "Learn to heal!" -- says the rogue pulling the entire room while the tank is waiting for the casters to regen mana. "[expletive deleted]," he goes on to say. These experiences really bother me and I just can't deal for a while.
Even though random raids are the same size as many battlegrounds, they're still more personal. It's better to have teamwork in BGs, but you can still get benefits from a frustrating loss. But you must work together in a raid in order to progress through it. Yes, there are still the generalized "this raid group sucks" comments, but you're much more likely to get a personal verbal attack from a funsucker in a raid group than in a BG.
A recent Drama Mamas covered a player's skittishness about grouping because of some hostile players. She has been avoiding groups for the most part ever since. We've all had terrible PUGs. It's the funsucker's role to suck fun, after all. But not everyone quits randoms afterward.
Do you pug? If not, why not? If you do, what is your advice for getting back in the saddle after a bad experience?