I think the problem with CGI is that most everyone ignores the physical laws of science. So even if we cannot tell the difference between CGI and the real thing, it looks faked anyway.
THIS. Right here, this is one of the biggest problems in CG effects today. It's painful because you could definitely follow actual physics/dynamics and get a perfectly real can't-tell-it-apart-from-the-world's-most-expensive-stunt, but you need very good effects people to do it and they're not cheap. Hollywood has learned that the average movie-going moron doesn't really care, so producers generally go with the cheaper, crappy-looking effects.
Heck, just look at the swinging around in the recent Spider Man movies. Had they stuck with more realistic-looking physics and motion those scenes would have been increcible. Instead, I felt like I was watching a video game.
For CG done right, take a close look at Davy Jones in the 2nd Pirates movie. Absolutely brilliant modeling, animation, and rendering. The first time I saw it I wasn't entirely sure if I was watching CG or an astounding prosthetic device.