Ancestral calling as universal rule yields morally indefensible outcomes.

Evidence

Must a man follow his ancestral calling even if it does not suit his capacities, even when it has ceased to be profitable? Must a man live by his ancestral calling even if he finds it to be immoral? If everyone must pursue his ancestral calling, then it must follow that a man must continue to be a pimp because his grandfather was a pimp, and a woman must continue to be a prostitute because her grandmother was a prostitute. — Ambedkar, B R, Annihilation of Caste_ The Annotated…, 1247