Gotta agree with OP, seen it too many times. Just last night did random duty only to get a tank that would not let up on this DRG. We were in Barx... what ever that lvl 32 dungeon is with the poison dragon fight. Long story short. Drg dc's just as fight starts. The remaining three of us trio the dragon. Tank then ends the day with telling us what p.o.s we are and was disgruntled for having even helped us level.

Wish I could say this was the first time I have seen something like that, but it's not. What the hell people?! It's only a game!