First of all, a lot of the grandiose claims here about how "if I was demented I would just get myself put down" are coming from tech people who could afford this end of the spectrum.
Second, 24 hour home care - or 'family care plus a certain amount of professional relief' is, while expensive, not much more expensive than medicalized fulltime care in a lot of facilities. You're not paying the overheads of a bunch of salaries and potentially the profit margin.
At the lowest end of the spectrum, things are indeed terrible. Aside from fairly extreme small government people, I think most people would want the state to step in. A lot of the places that are over-medicating their patients are collecting vast amounts of subsidies and pocketing the improved profits that come from getting to run staffing levels as low as they can get away with.