I agree that 3D is not a requirement. I enjoy it myself. I saw Avatar, UP, "How to train your Dragon", Monsters vs Aliens, and well... mostly CGI movies in 3D and they look wonderful. It isn't a requirement but the idea is for me to be happy. And if 3D makes me giddy, why not see it?
The surcharge I can also understand. Not just the projectors but those glasses. They cost money and probably quite a bit too.
But this is human technology:
We don't advance because it's better, we advance because we want to. We strive for something new, something more. 3D has been done many times before but now we finally have the ability to make it much better than the old "red and green" glasses. That's progress for progress's sake.