Generally the only time Nintendo does a "more of the same" sequel is after a very long (at least an entire generation) hiatus.
That's just not true at all. Animal Crossing. Super Mario Galaxy 2. Brain Age 2. English Training 2 and several others have been literally just that. By your argument, the smallest new option or mode can be considered a new idea for the series. Miyamoto's rambles about F-Zero just don't make sense. Bottom line is the game doesn't make as much money to the current Nintendo user base.