Except that's not what is happening with new players- who come into the game, get yelled at for healing in dungeons, get told by content creators to only heal at low health... then get into groups and are spamming damage spells as the group wipes over and over.

Letting people die when you can stop them from dying is bad play as a healer- you're talking about trying to fix bad play while you're encouraging people to play badly. When healers let people die- either intentionally like you, or accidently because they're tunnelling damage instead of healing or think that it's fine to not heal until low health and someone dies- sometimes they can recover, but sometimes they don't and you end up with a wipe or it spirals into deaths and rezzing and the boss takes 3x longer than it would have.

Yes, obviously if you get hit by mechanics you should learn... but from the other hand- if you're a RDM or SMN and you see a healer die to vuln stacks, are you going to be like 'well if I rez him he'll never learn! it's a two way street!', I hope not but maybe you would.

Whole picture- if the healer is intentionally letting people die that he could save that's atrocious teamplay, period.