This meme I saw months ago pretty well summarizes the attitude I see from a notable minority of healers in FFXIV. The thing that has this particularly on my mind was a run of Praetorium I tanked just now where the White Mage cast no almost no healing spells. After using my invuln on Nero’s tankbuster because I wasn’t confident I would survive it, I asked them pointedly if they had healing spells on their hotbar. They replied that healing wasn’t necessary on Prae except for the Gaius fight. I shot back that if someone flubbed a mechanic and died because they were at low health, that would wipe out their gain in DPS. I blacklisted them after the dungeon because I have no desire to ever play with someone who has that attitude. I hear that kind of heal-only-if-necessary approach is necessary for Savage content, but it strikes me as both callous towards the party and boring for the healer if you’re not actually healing.
This ticked me off enough that I went and healed a dungeon myself afterward. I was attentive to the party, prompt about topping people off as soon as they took damage, and got three commendations. So let that be the lesson: be kind and attentive, get praise; be callous, get blacklisted.