As I learned this to mean that the parents contention is not that the child is doing anything wrong but he is a drunkard and glutton. The reason they go to the bet din is to make sure that the Torah puts in safeguards against child abuse. I believe the Rambam had spousal abuse in mind when he alludes to bet din. In my mind to believe that a husband can beat his wife is barbaric. Men have authority over women because God has made the one superior to the other, and because they spend their wealth to maintain them.
Good women are obedient.
They guard their unseen parts because God has guarded them. As for those from whom you fear disobedience, admonish them and send them to beds apart and beat them. Then if they obey you, take no further action against them. God is high, supreme. I can only thank Hashem that our Torah approach towards our wives is light years ahead of everyone else.