Self imposed iron man doesn't fix the shitty aspects of games designed around the assumption the player will reload if bad things happen, which is what we're really advocating against. If you design a game with limited saving in mind you make a better game. You include ways to fail or lose progress besides death. You make dangerous situations take time to resolve and give the player a chance to react, so that if they fail to react properly it's their fault. You make the game worth replaying to try different strategies and see different content you missed the first time. You make the game worth playing even after bad shit happens to you, which gives you a whole different layer of situations you can be in instead of just being totally safe and prepared at all times.
Meanwhile, in reality:
"You have found a potion! Do you want to drink it? y/n"
"Yes"
"LOL, you die"