If you want to pay the extra taxes it would take to open up all the public mental hospitals again, no one's going to stop you. But in the meantime, mentally ill people are going to need equal access to housing, employment and other services and things. And opening the public hospitals won't be cheap this time. In the 50s and 60s, mentally ill people were literally warehoused. No one really cared if they had adequate medical, housing and other things.
Now one guy on a discussion page once told me, he doesn't care, throw them all in jail. But a doctor friend of mine once pointed out, that wouldn't be cheap either, because the money would still have to come from somewhere. But of course it would be inexpensive, because let's face it, cruelty is usually cheap.
So the choice is yours now.
All this plus the stigma people with mental health issues face. People have to want to help them and treat them as equals. I always say, would you think anything if someone with diabetes took medicine or someone with an infection went to the doctor? Most likely you wouldn’t. So why would you think differently of someone with a mental illness than you would of someone with a physical illness?
I agree with you that nothing is cheap. It would be much easier just to throw anyone/everyone that has such health issues into an institution. Like you said, it´ll still costs the tax payers money. So, why not give the people that are suffering such issues the medical attention they need/deserve? I bet you that if you did, gave them a job, affordable housing, etc that some of these people will get better and live a more satisfactory life. Why not give them a chance? I would.