well they closed the institutions long ago so just where did they think these people would end up? If not on the strets they’re in prisons...neither ‘help’ these people. And there are many who would not go willingly for help.
That’s the point of involuntary commitment. You cannot expect a person who has lost the capacity for rational judgment to seek help.
We have to help them for their own good whether they like it or not.
Better for them and better for society.