Re:"shouldn't change things"
Damn right we (as an industry) shouldn't change things. Imagine if every time you bought a new car the pedals were in a different order, and after you'd hit the brake instead of the accellerator you were told you should have practised more before going out on the road. With CUA we had a reasonable standard interface that was becoming widely understood, and changing with ribbons and things was a damn stupid idea.
And in many ways a car is a good example, because basically the user interface isn't very good and it would be quite possible to improve it, but...