... Except, we do? In fact, DPS players are held more accountable in this regard than healers. After all, they don't have a built in excuse to play inefficiently. No one agrees DPS who refuse to AoE are still good damage dealers. They're widely acknowledged as lazy and more frequently called out for it. There was even a thread here roughly a year or so ago where a RDM whined about Scatter spamming because "it's boring. I didn't wait in queue for twenty minutes to spam one button."
Funny how the whole thread called them out on being lazy.
Healers? We have this nonsense—where yet, again, you have a group of players willfully neglecting their kit because they simply want to heal even when the game doesn't demand said healing. We then receive a myriad of excuses or deflective arguments ranging from MP conservation to "LOL I'll focus on DPS then and let you die."
When have tanks or DPS ever been able to say...
"I don't want to use my CDs!"
"I'm an Archer not a Bard, I shouldn't have to sing!"
"Why should I have to move out of AoEs? You should just heal!"
And they not swiftly be kicked and/or made a mockery out of? Exactly. Only healers have an excuse—one people have long grown tired of. No one is asking you pull 7,000 on WHM. If, on the other hand, you're pulling 0 despite the tank and DPS doing their part properly, you're simply leeching off their work.