How many people (coaches, parents, players) actually take time to read the USA Hockey rule book? I would guess it's very few. Parents freak out because they see things on the ice they don't like and yell about it. Most, even if they have played hockey, don't know the actual rules since it's mostly information passed down that is outdated. That said, the kids know what they have been told by parents and coaches, but realistically, they think they know the real rules, but don't. So in my opinion, this is why parents go crazy yelling at referees and coaches.
USA Hockey is a joke, the kids should be checking in squirts! Learning how to give and take a check at an early age.