chadachada123 said:
It can have a negative effect if done badly. One way that 3D movies are made is by a process that darkens the film considerably. If the film is already not incredibly bright, it can make the movie near-unwatchable.
Regarding the "it's a gimmick" reason being given, it's not that being useless is a bad thing, it's being useless but *charging more money for it,* particularly if it's the only version in theaters, that is the problem.
"It can have a negative effect if done badly."
So can every other aspect of filmmaking. That's hardly an argument against the very use of the technology. When done well, it has a positive effect, and when done badly, it has a negative effect. That's how things work.
As for costing more money, I've never seen a movie theater that had a 3D movie without also having the 2D version. That means that those who don't like 3D don't need to spend the money, thus invalidating the complaint entirely. I could see how it would be annoying if the 3D version were the only one available, but as I said, I've never seen that.