Sorry, but are you smoking something? Nokia have a responsibility to aim for popularity: higher popularity == more device sales == higher profits. Now, there are many mechanisms for delivering popularity: including balancing quality, cost, development time, release date.
From my personal perspective the current UI's on the N810 are nowhere near on the level of being "good enough" that I would be scared of changing them, even drastically if necessary. If the current devices would have sold millions and millions and their UI's would have been praised universally, then there would be much more hesistance towards change, I'm sure of that. Popularity is a practical measure for success.