Personally, I love 3D.
Movies have evolved to approach the way we see the world. First they added sound, then they added color, now they are adding the third dimension. For me, it's not a gimmick, it's a step in the right direction in making movies look more natural. Just like bad sound, bad 3D can be distracting, that goes without saying. Doesn't mean that 2D is better than 3D in principle, though.
Just my two cents.
I get headaches watching 3d and it gets blurry sometimes. Mi oftalmologist tells me that i dont have proper strereoscopic vision, so i might make too much of an effort to get a proper image in my brain; a friend of mine has 3d forbidden by his oftalmologist because of a contition he suffers in his eyes since he was a child, he could eventually loose his sight due the strain watchin 3d.
I dont have a problem with 3d in itself; but if 2d screens get lesser and lesser or their conditions of less and less quality, then we have a problem. And in small cities in big countries, its getting more and more dificult to find 2d coppies.
Thats not fair; to some, its a question of preference; to others, its a condition.