I think there's a lot of overlap with homeschooling and completely bonkers evangelicals. Or anti-vaccine hippies. Or Scientologists. Or any number of odd reasons a parent would want to keep their kids away from public schooling. So that probably has a lot to do with why the kids come out strange or traumatized. It probably can't turn out well for your teacher to be the same person telling you public schools are full of Satanic gay witches who will drink adrenochrome out of your blood.

There are probably a lot of pretty normal parents who homeschool their kids, probably works out pretty well in some cases. Homeschooling is often the only option for kids who are disabled or neurodivergent in some way. I know someone who was homeschooled because she had really severe ADHD and her parents felt the school system wasn't treating it well. She's actually normal and cool. Another I know simply lived way out in a rural area and it was easier to homeschool than to drive them out 35 miles to the nearest school every morning, although he's incredibly weird and once told me there are homosexual hypnosis messages in Hollywood movies. His parents also told him the south won the civil war.