If you adopt Benedict's position, Kluckhohn suggested, then you can't be critical of evil as you notice it in the world around you, whatever your favorite examples of evil may be. To replace Boas' and Benedict's relativism, Kluckhohn proposed a set of ethical and cultural universals that, to my ear, are surprisingly void of content. These are really different ways of giving meaning to one's life, of displaying one's identity, of being in the world. A people either prizes their own norms or they don't have any norms. Similarly Kluckhorn argued that the variety of human moral standards contains a universal.
All cultures have moral systems.
I would think that's fairly true, except that I don't feel especially enlightened. To say that we all have moral systems and then not to say what the moral standards are is not very substantive. At the same time Kluckhohn was looking for cultural universals, he was also something of a relativist. He said many different values in human cultures are not so much ethical as they are matters of taste. The fact that the taste of other peoples does not coincide with our own does not make them stupid, ignorant, or evil.