In the past I’d be inclined to agree with you, however I saw two movies in 3D last year and it changed my opinion.

I saw Jaws in 3D (not to be mistaken with abomination that is Jaws 3-D) because they only rereleased in that format last summer. I absolutely loved it. I didn’t find myself noticing any bad 3D conversions and on a few occasions, the 3D felt like it enhanced some of the shots.

I also saw the most recent Avatar in IMAX 3D and that was a visual spectacle.

I really think the technology is starting to catch up and we will see 3D movies become more seamless and polished in the next few years.