Well here is the thing about Roguelikes and pernament death.
Some Roguelikes use it as a crutch as I said... It is a way to say all the game's flaws are actually benefits. Even Netheck has a few of these. The worst of these are what I call "WikiRoguelikes" or rather roguelikes where unless you are insanely obsessive you HAVE to use a Wiki in order to genuinly beat the game.
When pernament death really shines is when the roguelike comes together and feels like a cohesive whole. When all the skills you have earned from playing come together and you get through it without exploits. When the game lets you know what is happening and you are just outright dying.
The First few floors of IVAN for example are an excellent example of this. After you really get the hang of the game, you will pass through these almost everytime (The game melts to crud after the Ennerbeast... the EnnerBeast is also sort of unfair). Is the game super deadly that will kill you at every turn? Yeah... but the skills you get along the way are real.
Basically since you like Chess Imagine there was a good and bad version of Chess
a Good game of chess would have around the same rules it does now
A Bad version of Chess would have it so if you don't make the best move possible... your opponent could declaire themselves the winner and flip the board. No discussion, no debate, in fact most of the time they won't even tell you. Plus every 1 in 5 games the opponent can just flip the board and say he wins for no reason.
This is why I don't really think Cult could function as a purely hardcore game. Under its philosophy it seems more then possible to randomly run into something way stronger then you are without knowing it is that strong. Heck I even question the value of even the option for a hardcore mode (Except the one that lets you play as your family members, that actually has a lot of potential)