I don't think you can look at what Nintendo does in that light, especially because of the usual sense "rehash" is used in.

For example, COD(yes i know this is the obvious dead horse, but it is so for a reason). It is a fact, that every game since COD4 till present is running on the SAME GAME ENGINE, updated yes, but the same game engine. Virtually the exact same game mechanics. Same for games like "Madden".

But then you have Nintendo. Lets look at Mario. Every console has had a different style of Mario, platforms all, but incredibly different and yet people love them for the same reasons.

THAT is what makes Nintendo awesome, its that they can make games that both the aspects of being different and the same add to the game. Zelda, while not as much the same recipe, is mostly the same.