And I would suggest it not just for gamers but for programmers as well. There is a lot one can learn about user interfaces, shells, coding, architecture, data management (items, races etc are all data) with the additional motivation to learn it while playing.

On the other hand DCSS's game design is pretty stellar in my experience. It's better balanced than Nethack and relies less on arcane knowledge to get through the game. I've always ended up being frustrated while playing Nethack blindly because it feels unfair, meanwhile when I started reading spoilers I felt like I was cheating. DCSS handles that a lot better I think.

I think it took me a couple years to ascend without cheating, I don't know whether to cry or laugh at my former self :)

Btw, I think modern nethack playing is quite different from the old times, because of the amount of easy to find information (i.e. wiki,guides etc).

Playing without spoilers is more interesting but can become frustrating much faster.