There's nothing wrong with well-executed 3D Mario. They're fun games, when done well (and Super Mario 3D Land was done VERY well). When a publisher sells another 3D game--which is what many, many people want--that's not shoving something down our throats. It's responding to demand. I like the classic 2D stuff too (though in general, the New Super Mario Bros. games have fallen a bit short), but franchises need to evolve to remain relevant. Not every game can be a throwback. Super Mario 3D Land made nearly all the right moves.
"Too often we enjoy the comfort of opinion without the discomfort of thought." - John F. Kennedy on reality
"What if everything you see is more than what you see--the person next to you is a warrior and the space that appears empty is a secret door to another world? What if something appears that shouldn't? You either dismiss it, or you accept that there is much more to the world than you think. Perhaps it really is a doorway, and if you choose to go inside, you'll find many unexpected things." - Shigeru Miyamoto on secret doors to another world