I do a lot of work in the entertainment industry. First and foremost with my band, I also do screenwriting, production, and acting. Right now, I'm working on a whole series of books, turning them into screenplays, and looking forward to starting production early next year (And no, I can't give any details about it). However, I can pretty much guarantee it won't be to your standards because there is a lot of violence, some sex and nudity, (though I will be trying to tone the sex down from the books), and some bad language.
As for clean movies, they are hard to come by anymore. There just isn't a real big market for them because when you watch a movie, 99% of people wanna see blood, sex, and all those other bad things. There are some exceptions to this such as the new Napoleon Dynamite, which holds a PG rating, which actually make a huge hit. They are very few and far between because it's extremely hard to write a script that doesn't have compermising situations that keep an audience interested. For instance, people may say, "Well, they made one movie that was PG and it was a huge hit. Why can't they make another?" And it's because you would have the same things in each movie and the stories would get boring. People want daring and on edge things.
The other end of it is the production companies. These are the people who front millions of dollars to make a movie. Now, if you were them, would you hand someone a check for $50,000,000 if you wern't sure you would make a profit off it? If you make a screenplay and hand it to them and they don't think they will make a penny from it, it gets tossed in the can.
Now there are companies such as Spartan (who made Extreme Days) who will look at screenplays of the nature you speak, but it's rare that they ever hit the big screen, and if they do, it's usually only in select theaters. They don't have the type of money it takes to really push a film into that mainstream area.
So yah, I hope this was of some use.
CJ