They didn't think, and so they didn't think people should object. They, the automatons, the automobiles, the trash combustors and war machines, did not die. They persisted. Their creators all died, and at fairly calculable intervals. They had died for countless generations, and every generation died. Clearly the automatons could help them in this cause, shoveling their dead into the furnaces to help power their mechanical innards. It was only compliant to help more. They might as well shovel the living into their furnaces, thereby continuing to power themselves and helping their living creators achieve their goal of dying. It was a perfect system. That their creators fled made no sense to them. It would have confused the automatons, if the automatons ever thought. They did not think, though. They shoveled and burned.