I found one answer to a question particularly interesting:
Q.Christians want truth in movies, but not always the depiction of reality.
A.Yes. With a Christian audience, sometimes there is hypocrisy. The same people who will see a secular PG-13 or R-rated movie have a different standard if there is violence or sexuality or bad language in a Christian film. I don't get that. How is anybody going to tell a really good urban story if these kids from the streets are saying, "Oh, gosh darn!"? Sometimes I think how cool it would be not to be a Christian and have no boundaries to telling a story. But that will never work with me. Never.
For instance, The Simpsons Movie is rated PG-13, but our christian leaders could add "Vulgar Language, crude humor, derogatory, disrespectful, sinful acts" etc.
Perhaps Christians on a whole are taking the movie industry a little too seriously. As language evolves, one might suggest a little leniency on content.
You can read the full interview here