You seem to have missed the point. This film is targeted for children. In releasing it before Christmas, many unsuspecting parents may naively purchase the trilogy of books noted above. And that is where the author intends to deliver his message; not through the movie.
I understand. Children tend to be far more resilient than we give them credit for.
That being said this is a parenting issue so it's not for me to stick my nose into what movies parents let their children watch. My wife and I use to screen all my son's movies and books. There were times I would go to a movie prior to my son and watch it just to make sure there wasn't something wrong with it. So I can understand where people may be coming from on this. In one way, I would rather have my son go to something like this than overhearing the nightly news with the constant discussions on rape, murder, homosexuality, etc. I use to tell my wife to turn off the TV or go into another room.
If a parent doesn't feel their child can handle this type of movie, then they shouldn't take them. However, don't believe for one moment that their friends won't be talking about this in detail at school. They might even want to check the book out at the library if it hasn't been assigned in school. In the end, all we can do is to try to bring up a child in the best possible way and commit the rest to the Lord. It isn't in our control.
But what makes it so much different than a lot of other godless entertainment targeted at children? To me it seems like just another drop in the bucket. I enjoy Star Trek, though it's obviously humanistic and anti-Christian. Suspension of disbelief does wonders I guess. Some of it I don't like and I don't really go out of my way to watch it. But I would argue that the same message is present in a lot of entertainment, not just this particular movie.