Most people cannot and will not live up to the strict moral standards of some five year old on their high horse. When the five year old screams "The emperor has no clothes and you're a liar!!!!" multiple times per day and will not stop when punished for it, it creates a lot of problems.
One of my sons was like that. I homeschooled and I can live up to his expectations for things like fairness and keeping my word. But when adults don't live up to those expectations and they have some tyrannical little would-be civil rights activist on their hands, it sometimes turns abusive because they need the kid to just shut up and give it a rest already and they run out of ideas for how to keep the kid from being a troublemaker. (Alternately, in school, they are constantly in detention or similar.)