That is why many people are in the business. Money. They don't give a damn about the kids. So they smoke outside and feed the kids nothing but Spam.
Great.
Some don't while others most likely do.
Foster care is a type of home-based employment, and like any other employer, the state can tell you what to do while you're at 'work'.
IMHO, it seems like children were better off while we still had orphanages instead of being shuttled around from foster home to foster home. At least that way they had a stable environment.