hall of the novice wrong?

[Rongway]

He specifically clarified a couple posts above that he's not talking about aoe situations, but about people just single targeting mobs other than the tank.

Yeah, well, wall of text started writing itself long before that post.

@Op: if that's the case in levelling dungeons, chances are people are new and simply don't know better. Try to remind them friendly to please focus on the target of the tank. There's also the option to mark the one you're on. That was rather common for a while, but kinda got out of fashion. If they still hit other mobs and give you a hard time, you can only deal with it, do your best to hold hate and finish the run, kick them or leave yourself.

If even one person has DoTs or AoEs, the other people who are single targeting should be hitting the targets that have the most health, so that individuals live longer, but the pack as a whole dies faster. So the point stands: tanks should AoE liberally and not focus on one target.