Another culprit is marketing of films.
Many projects, not all, are started with marketing in mind. Lots of times, film execs choose an actor or actors first. Who's hot? Who can they sell the chosen actor to? Then they try to choose a script for the actor that makes the actor all sparkly to his/her fans.
But, then, just to be safe, the execs will try to pick a script that they know they can at least sell the DVDs with.
Which is why this year alone, there are over 20 films (of movies I could think of) that are either remakes, or movies based on TV shows. The sure thing is the nostalgia factor.
They know people will go see movies like "bewitched", "The honeymooners" and yes, even Batman, because people are comfortable with what they already know.
It seems like rule number one now is never challenge the audience.
I mean, batman was an alright flick, but it's Batman. I know about Batman, everyone knows about Batman. We all bought tickets to a story we already know.
The same is true for King Kong coming out this year. We all know this story already.
Personally, I'm disappointed in Peter Jackson for choosing to do King Kong. The man had a golden opportunity to do something really daring, challenging, and ORIGINAL!
Jackson had the world eating out of his hand after Lord of the Rings, yet he decides to go the safe rout and make Kong. Yes, it will probably be cool looking, and a good film, but at the heart of it, it's still just King Kong, which I have seen 2 versions of already.

Some people have said the same thing about Star Wars, and Lucas doing the same movies. But I think it's different. Lucas was telling a story that took six movies to tell. Furthermore, you went to every episode not knowing what was going to happen. The Star Wars saga is an original story, not a remake.
Quintin Tarentino is another original filmmaker, and I love the guy for it.
Quintin did what all film makers should do, remember that film making is art, and that through this art you have a unique chance to communicate, and challenge people or to give them something they have never seen.
So it's not for a lack of good scripts, believe me I have read some incredible ones coming through my buddy's hands. We get bad movies in the theatres because the big movie companies won't take chances and make movies that aren't SURE THINGS.

There is hope though.
1. I think the ticket sales reflect that people don't want what's being offered. The movie that made the most money this year, by more than $147,000,000 was Star Wars, an Original film.
2. Thanks to innovators like Lucas film, it's becoming easier and easier for independent film makers to get there wonderful original stories made, and with out any dependency on big movie studio's. Soon, by way of direct upload to theatres, filmmakers will be able to bypass the big film studios all together when they no longer need them for distributing. Then we will once again have variety, and original films in abundance.