I think they didn't have enough 3D movies to show that was part of the problem.
There are a few factors in why it didn't take off earlier than expected.
Not many movie theatres were equipped with digital projectors due to the costs and that it wasn't simply good enough compared to the film projectors until a few years ago.
The 3D camcorders (video cameras) were incredibly expensive, which is why a lot of studios didn't go with 3D movies for the time being. They were also unconvinced that it would bring in more money. They were right because there weren't enough movie theatres capable of projecting the movies in 3D. Only a few would experiment with it. In fact, James Cameron was the one pushing the technology years ago. He was heavily involved in developing the high definition 3D camcorders, he experimented with them by using them for his documentaries. There were some movies that played with it too. For example, Spy Kids 3-D. Unfortunately, they had no choice but to give out the red and blue glasses since they didn't have the digital projectors at the time.
Now, regarding the IMAX technology. The reason why not many movies were filmed using IMAX technology is due to the costs of the equipment and the film negatives. They are far more expensive compared to 35mm film negatives. 35mm is the standard in Hollywood these days. There were a few movies back then that were filmed in 70mm, which is what IMAX use. Ben-Hur was fllmed using 70mm film negatives.
The film industry is now becoming more comfortable with the 3D technology and now that the 3D technology is now becoming more available in the home theatre industry, things are going to change even more.
There's a lot of factors, that's for sure.
However, I do believe the 3D craze is just a trend right now. We will see a lot more 3D movies in the coming years, but we'll see that they will be on the decline. We'll still see 3D movies, but just not as many as we are seeing right now.
