That is a false comparison. Most people I know who work in radio do so because they are drawn to something about it, whether it's the music or the other people or simply working in a studio with all of the equipment. So making whatever sacrifices about working conditions or pay tends to be an informed and willing choice. I suspect few, if any, people working in Amazons warehouses are doing so because they love working in a warehouse.
Employment, being a contractual situation (because SCOTUS has repeatedly said so), is about a mutual, reciprocal exchange of value. If the value Amazon is attempting to extract from their employees is not reasonably commensurate with they are paying, then Amazon is deficient in holding up their side of the agreement. If the conditions under which the employees are working are unreasonably onerous or unrealistically sustainable by an average person, then Amazon is not only deficient, they are willfully so, which under contract law, puts them even more in the wrong.