Agree with thelaptop but I'll use more words.
DoomRL gameplay is a one-shot deal. Your performance one game is independent of your performance of the next game.
However, I agree that it does not have to be this way.
A very fun game can be made out of a 'career mode' where you can directly affect subsequent games with your performance in the current game. Desktop Dungeons does this well.
To properly pull off this kind of game, it basically needs to be designed this way from the ground up. Attempting to tweak the current DoomRL to support this type of gameplay would likely result in failure on both fronts. Given the lack of time the dev team has with DoomRL right now, it's simply not going to happen.