This line of reasoning doesn't defend their practices nearly as well as you think it does. For instance, paying homeless people to fight each other will certainly make sure they have money for food, and it might provide them some much-needed organized activity!
If the reason you help someone is because you want to sell them something or use them, you're doing help wrong.
If the reason you help someone is because you want to sell them something or use them, you're doing help wrong.