> Yes, if the product is seen as bad for the world, it won't sell. But it's pretty bad for people, and I don't know how you'd hide that for the people being harmed.

That's not true. There are all kinds of products that benefit certain people, so sell, but are overall harmful to the world or a harmful to much larger number of people than those who benefit.

> and I don't know how you'd hide that for the people being harmed.

The trick is to make the people being harmed too powerless to stop the harm being done to them. Then your problem is solved and everyone (who matters) is happy.