In a nutshell, the audience for nuanced, elaborately plotted scripts is not as big as that for epic hammy ones. The movie industry (qua theaters) is not really about movies so much as it is a marketing operation for comfy chairs, sugary drinks, and popcorn. Hence the big-budget movie emphasis on the 'wow' factor, best appreciated via a 75-foot screen.
To some extent, it's always been this way. Look at Shakespeare: most of his plays are set in foreign countries which would have been terribly exotic to his audience, or are concerned with battles, magic, or murder - it's all pretty sensationalist stuff.
With this sort of big-budget production story complexity takes a back seat to putting the audience 'into' the experience. Gattaca is a fine sci-fi movie that turns on a clever script and strong acting performances, but it wasn't exactly a box-office sensation. But it was pretty cheap to make. with something like Avatar you want a story that everyone can follow easily rather than one that risks alienating any segment of the audience. Epic stories generally try to minimize ambiguity and complexity: the payoff is emotional rather than intellectual.
It doesn't have to be complicated, but at least it should be realistic. For example it bothered me that the flora and fauna on Pandora was completely unrealistic. I don't think horses would have a very good time in the jungle, for example. If it was realistic (ie adhere to evolution theory), then one could still learn something from the movie, even if the plot was shallow.
Likewise in terms of evolution theory, I wonder how/why would loads of animals evolve with a common digital port. Not saying it is impossible, but then the history of that would be seriously interesting (I suppose the whole world would have to be an artificial creation by an ancient high tech race or something).
Instead, this movie dumbs down the common public by reinforcing naive stereotypes.
What amuses me in that context is that for example, the real native Americans did not even have horses before the settlers arrived. This just shows to me how extremely shallow the research for Avatar was. Of course natives have to ride horses and scream passionately and engage in stupid fights and rituals.
It bothers me because as it happens, I consider artificial life to be one of the most exciting things. There would have been so many opportunities here.
It's also true that if you're spending $300,000,000 making the movie, it's got to play everywhere. EVERYwhere. It's going to be translated into 50 languages, usually badly. It's going to play in villages where no one reads and no one speaks English and the sound system loses half the words anyway.
Simple works. Complex doesn't.
As foreign box office has grown to a higher and higher percentage, this has become more and more true. Avatar did over 2/3rd of it's global box office opening weekend outside of the US and Canada (the "domestic" market).
A simple script isn't the same thing as a bad script, though. Star Wars, Raiders of the Lost Ark, Die Hard, Alien... these are simple scripts, but they were all turned into good movies.
The problem with Avatar's script is not so much its simplicity, but its preachiness. A story set in a simplified world of good and evil isn't so annoying (cf Star Wars) unless it's supposed to be making some kind of political commentary on our own world.
To some extent, it's always been this way. Look at Shakespeare: most of his plays are set in foreign countries which would have been terribly exotic to his audience, or are concerned with battles, magic, or murder - it's all pretty sensationalist stuff.
With this sort of big-budget production story complexity takes a back seat to putting the audience 'into' the experience. Gattaca is a fine sci-fi movie that turns on a clever script and strong acting performances, but it wasn't exactly a box-office sensation. But it was pretty cheap to make. with something like Avatar you want a story that everyone can follow easily rather than one that risks alienating any segment of the audience. Epic stories generally try to minimize ambiguity and complexity: the payoff is emotional rather than intellectual.