That seems a bit self evident, but your issues seem to come down to you not enjoying/not being good at the game itself, but somehow still thinking you should be having fun?
I'm plenty bad at plenty of high difficulty games. I sucked at Binding of Isaac for the longest time, but I have a great time even losing in Binding of Isaac, because they make the actual playing of the game whilst losing fun. I may lose, but I collected this item, got these items together, looked this way and gee, I can't wait to get back into game!
I don't feel that way about this game. Losing isn't fun, it's a tedium. That's what I mean about the difficulty covering for the fact there's not a ton of game there. "Gee, that 4 minute run only to be dumped into a pit of spikes was....boring. I can't wait to....get handed basically another room like it on my next playthrough."
So yes. I think even when you're bad at a game it should still be giving you entertainment, and this seems stretched really thin on the fun when you don't get anywhere/do anything meaningful. I barely even glance at my descendents now. I only do so to verify they don't have the worst/stupidiest traits. (Again, your descendents is what made me even care about this game in the first place. Turns out, it brings next to nothing to the table. It's "cute" and that's all.)
I think this all ultimately has to do with the fact that while the roguelike/RPG aspects of the game were really played up, this game is really a platformer first, everything else second and third. And as I said, sort of how I don't find the repeated failure in Super Meat Boy fun, I don't really find this fun either, despite all its trappings.
TLDR: if you don't like hard ass platformers, avoid this. It's not an RPG, despite looking like one, and it's not a roguelike, despite borrowing from them. It's a platformer with stats and a hefty grind.