What pisses me off more than DPS who cannot attack the correct the target are the tanks and healers that decide they should just let people die to "teach them a lesson." I hate making a dungeon run longer than it needs to because I feel I need to punish those that don't listen. If I'm tanking, I'll just make sure that I'm putting in enough threat onto other targets so that no one pulls aggro, and as a healer I'll just toss extra heals if someone does get aggro (although at this point I would prefer if the tank could keep aggro on everything... it's not hard as a paladin so I would assume warriors have it much easier).

While it would be great if everyone did what they're supposed to, I still feel it is the tank's responsibility to keep aggro on everything and the healer's job to keep everyone alive, even if it means you have to pick up the slack of others. I'm not there to teach people how to play, I just want my experience and tomes so I'll do what I can to finish as quickly as possible, and letting people die does the exact opposite. Plus it would make me feel like a huge prick if I was to do something like that.