Problem is that it's a form of elder abuse - some of the most vulnerable are those that are mentally unable to be proactive - they're sick and they're tired, and might not be aware of their rights, and if they're alone in the world, it's them or nobody.
I remember an elderly couple - friends of mine - that came from England. When they came to Canada they were given a Dr who they didn't like but thought they had to keep him because they'd lose all medical care if they refused the Dr. Figured the Dr was "assigned" to them and that was it.
Then, when she had to have a heart bypass, the Dr "touched something he shouldn't have" as he put it - ie: her vocal cords, during the operation. They had to do an emergency Tracheotomy on her and put a hole in her throat. The hospital told her the Dr had moved. She had to buy tubes for her throat, and it was costly. Years later (9, to be exact), I met them, and told them they should report the Dr and get the College of Physicians and Surgeons to pay for the tubes ($200 / month) and get the Dr up on charges (he hadn't moved, we found him by accident). There was a 10 year moratorium on reporting him, so time was short. Because it was left so long, the College decided that it wasn't an issue. It was dismissed and she got no help at all.
And this was because they didn't know they had rights, and were shy about pushing to get something done for them.