In a way that's part of what makes it so interesting. It's not merely bad, the UX is completely alien. It feels like software designed by another species. There is loads of software with terrible UX, but most of it is bad in the same boring ways.

I see Dwarf Fortress as outsider art:

"Outsider art is art made by self-taught or supposedly naïve artists with typically little or no contact with the conventions of the art worlds. In many cases, their work is discovered only after their deaths. Often, outsider art illustrates extreme mental states, unconventional ideas, or elaborate fantasy worlds."

Other than the fact that the game was not discovered after his death, every other element of Wikipedia's outsider art intro paragraph fits to a T.