I will say objectively that I agree with the OP to an extent, those people are bad healers, but I would also direct you to my signature.

Also, while I know this will be responded to poorly, most wipes I experience are due in large part to tanks overpulling in dungeons, not performing mechanics/observing proper positioning in raids or being severly undergeared but you don't see a thread on every page about "TANK Y U NO TANK BAD TANK!!!1" and I feel like the healer criticism needs to slow down.