Why do Healers...

[Sleigh]

But also, some healers are elitist or have ego issues and use it as a way of saying "Screw you, you F'd up and died, so I'm going to make it obvious to the entire group by leaving you dead. And look at how good I am solo healing.

Some co-healers in PUGs are literally not worth the Swiftcast + MP + GCD to raise. That's not even me being an elitist here, sometimes PUGs won't survive the fight if you raise them, or they are so bad that your MP usage is that much more efficient than what they'll bring to a fight.