What really irks me about Dwarf Fortress is how simple it all is, really.
I don't mean the actual underlying guff, the various simulations are all... well, they're quite simulationy and I mean that takes time.
But the UI doesn't need to do that much! You slap down rooms, dwarfs go in the rooms, you drop some tools/whatever, you designate areas for stuff, you manage relationships a little. I mean sure it grows, but the basics are pretty basic!
The last time I quit forever, I was simultaneously building and assigning bedrooms one. at. a. time. and managing warriors in a half-implemented but massively important for survival system and realized maybe I could just leave well enough alone. I understand not bothering to implement a UI. It's not his wheelhouse, and he likes implementing new and weird simulated behaviour. But I can't stand when I see the idea presented that the ridiculous interface is a sign of the complex underpinnings. It's a sign of not putting any effort into a UI, nothing else.
I mean for goodness sake, the third party dwarf-manager is a practical necessity, and that's pretty easy to use!