"unless its just some kind of destructive way to antagonise people and seriously p*ss them off"
You've known forum trolls, prank callers, and guys who yell "Freebird!" at non-Skynard concerts, right? They like to game, too, but still want to hold on to their "most hated" status in this very different social medium.
I don't get it either, but I can't say I'm surprised. There's a portion of the population that enjoys antagonizing strangers anonymously, and some of them like to play videogames.