Having a huge ego and a big penis.
I am not hardcore, but damn right you should be penalized for not doing something successfully. It is a game, if there is no consequence for failure then there is no feeling of accomplishment for success.
Then leave the dungeon and start again - kill those trash mobs with no gear and re-level.
We aren't talking about piles and piles of EXP loss here. Enough to feel it if you die over and over, but a few deaths in a dungeon and you're gravy.. No one should be able to sit in the same empty dungeon for 4hrs, repeatedly dying to the final boss until they win.
