Why do critics argue that ethical relativism makes moral reform difficult?

Critics argue that ethical relativism makes moral reform difficult because it denies the existence of an objective, culture-neutral standard by which a society’s existing practices can be judged as deficient.1

If ethical relativism is correct, there is no external benchmark to appeal to when attempting to improve a society’s morality. Consequently, actions such as abandoning slavery or reforming oppressive customs cannot be viewed as genuine moral progress; instead, they would merely represent the replacement of one set of social standards with another. Because the theory holds that no moral principle is objectively true or valid for all people, it deprives individuals of the logical basis needed to raise moral objections against even the most harmful social practices, provided those practices are approved by the codes of the society in which they occur.1