When do wealthier people get to say what poorer people can or can not do?

Wealthy people tend to make all kinds of value judgments about what kinds of behaviors are acceptable. Maybe it’s more than wealthy people. In some cultures, there are “untouchables” who are only allowed to handle dead bodies, or human waste, or do the slaughtering and butchering. No one wants to be near them or associate with them in any way, if they are not of that caste.

In many cultures, prostitution is illegal. I think that to some degree, this is a patronizing thing. Women shouldn’t have to sell their bodies to make a living, so we make it illegal for them to do so. Organ donation is similar. The idea of selling organs makes us squeamish, but isn’t it patronizing, too? You shouldn’t make money by selling organs, so we make it illegal? Aren’t we saying the people who want to sell organs can’t make good decisions?

It seems to me that we are saying that people should not be allowed to hurt themselves in order to make a buck. At least, in some areas. Sure, you can go to work in a mine or a metal stamping factory, or in a recyling factory that exposes you to hazardous chemicals, and this is ok, even though these jobs have a good chance of killing you, either quickly, or slowly.

Is there some principle here that allows us to distinguish between these choices? Or is it purely the prejudice of wealthy people who can’t imagine themselves lowering themselves to that level in order to make a living?