Amen. I play mostly caster dps, but my druid sometimes tanks or heals, and I agree *completely* with this.
The tank has two key jobs, and they are tough enough. They must keep plenty of threat on their main target (either the first kill or the hardest hitting boss), *and* get some threat on every other mob in combat before the first heal gets cast. Healers cannot do their job without putting a bit of aggro on every mob in combat. Everybody else can choose who to put threat on, and it's their job to only put threat on things that the tank is holding securely or that they can handle.
As a mage, I will sometimes AoE and this is very efficient with large groups of low level or non-elites, but it's my job to wait for a situation where I have enough power and emergency measures to hand to keep myself alive until most of the mobs are dead, *and* to make sure the healer is ok with me doing this, in case I misjudge slightly.
If I misjudge by a *lot*, say I let fly with a blizzard or AE spam and end up being swarmed by 6 elites at 1/2+ health with FN, CC and blink all on cooldown, that is *my* problem and not the healer's or the tank's.
If I insist on doing dicey AoE with only one offspec or low-level healer in the party, I might be a moron.
If I'm not doing AoE and I regularly draw aggro that I can't handle, then I'm definitely a moron. It is not that difficult to keep from being hit as a ranged dps if we are controlling the fight. I should either be hitting the main target, or taking some easy mob where I don't need any help (or healing) to finish them off myself. Once in a while, I'll blow this and hit the wrong target by accident or get a crazy crit.
Oops. I should have snares available to keep my guy near the tank for a bit without taking much damage.
Or maybe not - in which case, help me if you can, but if not, let me die -- *my* problem.
If I do this repeatedly, it's not just a clicko and I would expect to be *booted* by a decent group leader if it was causing real problems.
Everybody blames the healer or the tank, but most of the time, the problem is some dps who doesn't realize that their job, while much easier than the tank's, is not just shooting anything that moves and yelling "heal me! heal me!"