Hey... my mom was a career psych nurse, too! Takes a special kind of person to work with that population....
There were indeed some terrible abuses in the old state psych hospitals. But they should have fixed the abuses, rather than decimating the system without proper replacement. There were other factors, too... such as advancements in psych drugs that experts (wrongly as it turned out) believed would reduce the need for hospitalizations more than they actually did... and the rise of the powerful patient rights movement that, well-intended as it was, has had terrible unintended consequences.
Basically, in the effort to fix earlier problems, mental health activists were able to swing the pendulum so far that if went too far in the opposition direction IMO. Now we have a woefully inadequate # of psych beds, and too many seriously mentally ill people bouncing between our jails/prisons, emergency rooms, and homeless encampments. It's hard to argue that what we have today is a more humane or civilized solution, because it's actually not.