Ok, you have a strong topic. Nintendo is a great compony for keeping tradition. Let's take Zelda for example. The game franchise is more than 20 years old and follows the same format: Go to a bunch of dungeons to collect a certain artifact to gain power to destroy an evil lord (ganon, vatti). In the dungeon you usually find an item that will help you progress trough the game to areas you need to go to to get to the next dungeon or to fight the boss with.

That same format was used in virtually every Zelda game. Yes, it's very solid. No one can beat nintendo's way of crafting an adventure game like this. Sure developers try but usually fail, or come really close. Some people are tired of these things in Zelda and want something way way different that bends the franchise into a new genre, so they talk about it and word gets out about some great idea for a new Zelda. Two years later Nintendo make a new Zelda game, and it follows the exact same way to explore and play the game.

So in short, Nintendo doesn't want to radically change a game genre or gaming as a whole again.