The Importance of Insta-Death

I feel like there should have been more of the DM kind of foreshadowing what was going to happen. Insta-death doesn't teach a lesson. I think it creates a grudge. Even gods should probably have to roll though to stomp on someone. You know, this exact thing happened in campaign one with Beverly. And what he would say is just do like 70 damage to them instead of flat out killing them.