I agree that movies shot in 2D should not be converted to 3D, but that's about where that ends.

3D quality is dependant upon the theatre. I go out of my way to travel 20 miles to one that has a DLP screen the size of a three story building. In that theatre, the 3D is truly amazing for movies shot in 3D. As for the quality of Avatar? The BluRay didn't come close to doing it justice to the theatre I saw it in.

If you are disappointed in your theatres 3D, find a better theatre!