Like put constructions and digging designations in the same menu.
As it is one of the things new players have to grasp is the difference between designations, constructions and buildings, especially given some of the overlap (carve out a stair vs. construct a stair in carved-out space); I don't think putting the potentially confusable subjects into the same menu would help that situation.
That's not to say the UI couldn't be made more intuitive, but just to say that it
is organized, just more by the game's distinctions that you have to learn than by the natural sense of "hey, where's the menu for building a house? What do you mean that each step has a different menu?"
If the game had a better UI and better graphics the community would grow massively. The larger the community the more donors.
It's not a something vs. nothing tradeoff, it's a something vs. something tradeoff: it's not "game as it is now vs. game as it is now plus UI/graphics", it's "game as it will be in so many years vs. game as it is now plus UI/graphics". Imagine, for instance, if Toady had started work on graphics about a year ago -- there would be no minecarts. Consequently, you can't just say as a granted that better UI/graphics would increase the community, because the question is whether it would increase more with better UI/graphics or with more features (and bugfixes). You could, of course, weigh those things and come down with an opinion on the same side anyway, but it would be much more reasonable than just saying "graphics is better than no graphics" without considering what "no graphics" is developing.
Relatedly, people I know don't like having to relearn menus much more than they like having more complete ones, and it's probably been mentioned by now that Toady expects elements of the interface to change because of the expanding and refining of the features they control.