Most game companies are afraid to take risks. Why should they spend a ton of money on a game with some avante garde style that might very well flop and lead to the end of them? If they own the rights to some big hit series like Halo, or Call of Duty, or God of War, then why not keep churning out sequels? If you're a company that doesn't have rights to such heavy hitters, but the engines aren't restricted, then for the most part, you know that such a formula has worked in the past. If you're interested completely in the money, it makes sense to make something that follows the "template of success" and hope there are enough differences that gamers will be attracted to the same gameplay style but not immediately discount it as a rip-off.
As for Nintendo, as if they hadn't had enough with the OoT remakes. The original, I will say, was great, for the N64. Then they came out with some version that could be played on the GC or something. Then that was compatible on the Wii or in their online store or something. And now, guess what is one of the only games for the 3DS worth mentioning? Yeah, OoT in 3D! Woooo..... Excitement not quite there.
It doesn't have to be innovative in terms of gameplay either. Sometimes it's just weird. That lightsaber game on the Wii? Yeah... Then again, almost everything on the Wii. RE 4 was good though, as were the Marios. But the ones that tried too hard to make the motion control some sort of great amazing thing? Not sure about that.
Then again, I might not be satisfied until there comes a time when we can plug our nervous system into a console and have the game stimulate sensations exactly as if we were actually experiencing them.
