"Harmless" zombies? The pre-Romero kind, of Haitian and African folklore, were used as slaves. Lacking any will of their own, and possibly limited in degree of consciousness, I suppose they might be considered the equivalent of robots. Even conventional thralls seldom had any rights, going back to
ancient Greece. In a post-apocalyptic scenario, the survival and potency of contemporary human and animal rights activism would, of course, be dubious indeed. So even though one could make the case from today that innocuous zombies should deserve better treatment because of either their anthropoidal appearance or "former life" as an ordinary human, the members of a resource challenged and philosophically crippled society might at best only domesticate them as slaves. While either exterminating or driving-off the wild ones that were pests (digging into garbage cans, breaking into grain / food storage areas, ambulating aimlessly about in public areas reeking stench, etc). And yes, the field-hand drunks shooting at them for sport and the wealthy landowner releasing the hounds and blowing the horn to commence the zombie hunt.