Fun facts that N haters like to ignore.
1. Nintendo was NEVER a hardcore console. It was always an entertainment system. They where always making games that will appeal to children from 1 to 101 years.
2. People buy Mario games because they want the Mario formula + 1. Same goes for any other franchise. People buy CoD because they want the CoD formula, Mass Effect because they want a Mass Effect, etc. If you change the main formula, it's not the same game.
3. Nintendo games have much bigger changes than you give them credit for. They usually just keep the core elements of the game. There will always be a Mario, Link and Samus. But the rest changes. Link will always have his trusty sword, Mario his jumping on top the the enemy and Samus her suit. If you change those parts, you can just rename the game and make a different game. Do you really want to tell me that the Wind Waker is the same game as Ocarina of Time? Or Skyward Sword?
The games will always be similar, but that's the point of a franchise.
5. Nintendo isn't milking their franchises to death (Mario more or less, but he's still fun in all his weird sport games). There is usually a 2-3 years between 2 Zelda titles, much more between Samus and around the same for main Mario titles. That's not milking. Milking is what Acitivision did with Guitar Hero (1 game very 9 months with no changes at all) and is trying to do with CoD games. 1 game per year. If we take all the CoD titles, than it's even more.
Milking is what Square Enix said they are going to do with the FF franchise. 1 per year.
Nintendo take some time to make the games. The time between 2 titles is enough for people to really want to play a new title in the series.
7. Not every title needs to be "the next definition of 'creative' ". Games are for fun. If you have fun playing a game, then that game was worth it. I don't want every game to be some piece of art worth to be in the Louvre. I prefer my games to give me a lot of fun during and after my playtrough.
8. Nintendo did more innovation than Sony and MS together. They at least try to innovate. Going for innovation isn't a guaranteed successe, nor does it guarantee to be a good innovation. But Nintendo at least tries. Sony and MS just copy Nintendo when they see it's successful.
9. Motion Controls are a great, positive innovation. 3D isn't an innovation on it's own, but it's a nice try to bring something "new" to console games (PC had this option thanks to nVidia).
10. You didn't notice I skipped 4 and 6.