I'm sure he doesn't completely reject the idea or he would disapprove of the magmawiki, dwarf therapist, soundforge, dfterm, graphic sets, mods, and more.
I wasn't talking about removing his interface from the game. I was talking about separating Core and Interface to allow the use of 3rd party interfaces, if so desired. Not many people play DF without 3rd party stuff like DT and graphics. I can see it being the same way with an interface.