He didn’t do anything to deserve this

Not all people are fit to be parents. They see typical teenage behavior, and instead of taking it for what it is, they act like their kid is irreparably evil. Some kids are genuinely juvenile delinquents who need to be set straight, but a lot of teens who receive cruel punishments from their parents do so for such minor transgressions as getting into arguments or not cleaning their room. Kids who are punished unfairly are in a permanent state of punishment: it doesn’t really matter what they did or didn’t do. Their existence enrages their parents, and therefore, they deserve punishment.

It’s tough to function in a household where you can do no right. It’s especially hard when you’re a teenager who doesn’t have real agency over where you live. You have to do what your parents tell you, or face their wrath. Even in functional families, teenagers don’t have much choice about their lives. When you have stable, reasonable parents, it’s not so oppressive to be a kid, but when your parents are out of control, you are forced to operate within a family system that harms you, and there’s very little you can do about that.