[People who don't care about themselves wouldn't see any worth to keeping themselves safe, leading to rampant self-sacrifice without a thought. He's seen that in Midoriya, and in All Might, though All Might had more power backing him.

Well, now... Midoriya is amazingly strong, but he still has those damn issues.]

A hero shouldn't be afraid to trade their life to protect someone. But a hero should be strong enough to never get put in that situation.

Sacrificing yourself should be the last option possible. You can't save anyone else once you die.