To say that there is an evolutionary advantage in something does not explain why it evolved the precise way that it did. There's an evolutionary advantage in language use; that doesn't tell us anything about the reasons for structural similarities in different, historically and geographically unrelated human languages. I raised the question of whether there is a deep structure to human moral systems beyond the simply pragmatic, analogous to Chomsky et al.'s hypothesized deep linguistic structure.

By the way, simply stating that a certain trait could have resulted in a competitive advantage in a situation which you consider to have been relevant in evolutionary time is not a proof; it's a just-so story.