Commendations to you and your family for the care you gave your relatives. OTOH, there are people who, for health reasons, cannot care for an Alzheimer's patient in the home. Everyone that I know kept their family member at home as long as possible. I don't know anyone who "farmed" anyone out at a "warehouse."
I've cared for a number of Alzheimer's patients, and they are different at different stages. Some do become violent, and I wonder if sometimes that's because of minor strokes that go unnoticed...in any case, it's an organic disease, and can affect different areas of the brain in different people. When a small, frail wife has a large, aggressive husband with Alzheimer's, she can be harmed, particularly after he no longer recognizes her.
It will all depend of their priorities.
When the age, they shouldn't be surprised when "family" doesn't have the time for them.
I hear "state homes" are horrendous. THAT is where they will wind up.