In this case (from what I could gather from the movie, at least) was that Brooke's (the head Fab 5 member, if that's her real name) parents divorced and the mom had never put much of a leash on her to begin with, and felt incredible guilt at the fact that her divorce had caused her daughter so much heartbreak. So she started indulging her even more, hence why we saw the events that took place. The school went through 5 cheer coaches in 3 years. Like
@OldskoolKYcheercoach said in another thread, if the school is practically changing coaches every year, it's a wrong indication that a foul system is in place. The mom and assistant principal were eventually fired.
I feel awful for all of the other girls on the team who's high school cheer experiences were crap just because of 5 entitled brats.