To be fair, CGI creatures look like a computer game regardless. A very pretty computer game, but still.
Sometimes it seems like people want to believe that CGI is a whole lot better than it actually is. People raved about Gollum in the LOTR films, but go back and look at it. Even at 24fps, it's not great. It certainly doesn't look real.
I agree with this but I think it is more complicated than people "wanting to believe CGI is better than it is", it is more like some sort of innate suspension of disbelief we all have as long as what we are seeing is as good or better than what we've seen before.
I lived through the entire CGI revolution in movies from the early days of Tron and the "Genesis effect" sequence of Star Trek II to now. The way the CGI in all the movies in between looks to me now is very different than it looked to me when first viewed and as a graphics nerd I was always interested and up to date on the technology was done. I don't believe my brain "wanted" to believe CGI was better than it was then, I just had no context for how it would look when it was done even better and as the goalposts moved what came before looked increasingly bad in comparison.
Incidentally, have you re-watched Fight Club recently? I remember when I watched it in 1999 I was completely blown away by the "impossible" cuts. I watched again a couple of months ago, and all I could think was that it looked like a Half Life 2 cut-scene. The standard for CGI rendering has gotten a lot higher. :)
I have wondered about this as well. Maybe the audience does not care so much and thus it makes no sense stay at stuff that can be pulled off with budget. That said there is more and more things that can be done well every year. I think something like Gravity looked pretty cool and it will be interesting to see if it looks good few decades down the road.
There weren't many organic things in Gravity. Mechanical things are much more easy to get to look right. (The easiest would be something made of plastic, I guess.)
Sometimes it seems like people want to believe that CGI is a whole lot better than it actually is. People raved about Gollum in the LOTR films, but go back and look at it. Even at 24fps, it's not great. It certainly doesn't look real.