They did talk about this before when people were mentioning how other competing games made healer sort of like how we have tanks, where they dps but also provide healing. Basically, they can't get rid of healers as they are because they'd have to nerf dps across the board for all dps and tanks just to balance out the fact healers now are expected to do damage, and then the fact the fights themselves are built around the healers having really insane levels of healing through comboing abilities. If they just buffed the heals to compensate the fights would turn into black and white mitigation strats, where a healer could heal someone from 1 to full super easy, so the only challenge is hitting enough mits so they don't fall over.