I'm the very definition of a salty WHM when I get put with a bad/ rude party, but I have never understood this mentality of "let them die." I mean:

Cons:
- You've just slowed the run down by 2 - 3 minutes
- It makes you look inept as a healer
- It makes you look childish
- The arguing, likely votekick or party member leaving - another 5 - 10 minutes wasted
- You're stunting your growth as a healer

Pros:
- A nice power trip for you I guess (???)

All because the party didn't wait for Protect? Really?

Coincidentally I'm also levelling AST, and not only do the lower level dungeons ease you in very gently, I automatically assume any healer worth their salt (eheh) would take the time to practice what's what before hopping into a dungeon anyway. Even as a newbie AST, I was hoping for big pulls/ chains to stop me falling asleep (and make full use of my cards in the sad life before Spread.) If every tank I got crawled by at the pace you're suggesting I'd go crazy.

This whole attitude comes off as being very controlling and achieves nothing more than giving obnoxious healers an ego boost, to be honest.