They're very abusive places which serve to hold and drug people against their wishes, till they die. Drugs that in fact shrink the brain of typical patients, have side effects such as causing diabetes, and were never intended to inwardly cure the patient but only to outwardly sedate them. Yes. That's what most neuroleptic drugs which they prescribe do to people. It's like treating someone with snake venom till they go into a coma against their will. Bad press.
Mind, I get the reasoning. It makes sense to hold someone who is erratic, beyond help, and dangerous. That is all extremely pertinent and valid. But please don't stop at only incarcerating the mentally ill for their lifetimes. There are potentially other ways of reversing their injuries.
Medical science currently has a wide range of emerging neurogenic treatments for brain damage. Structural brain damage underpins many debilitating forms of mental illness, particularly the type that might get someone institutionalized. Peptides that work on trophic factors, Hyperbaric Oxygen Therapy, BDNF agonists, TDCS with activity to induce plasticity, neurofeedback etc etc. For many forms of injury premised on brain damage (IE First episode psychosis), you can fairly reliably repair the injuries using such processes.
This is expensive and takes time, sure. I'm sure someone can figure out how to balance the books while keeping seriously ill people in containment. But psych wards are extremely traumatizing places for ill people and roughly akin to locking someone in hell. That's a hard trade in margin call cases