Earlier quoted context omitted.
Yeah, doesn't make sense. I prefer a simpler argument for why there is a subset of morality that's universal for (vast majority of) humans: argument from shared brain architecture. We're essentially running the same wetware under the hood, at least on the time scales of human civilization. So while the universe doesn't necessarily privilege a set of values, human brains are . And that's all that really matters (until…
There is an even simpler explanation: some moral principles push people towards a game-theoretic optimum, so evolution selects for it. Eg, a society that allows random murders will be at a staggering disadvantage. By magic, most (all?) societies have strong moral arguments against murder. Ditto honesty - honest societies have structural advantages. Any cooperative species will have something that looks like morality.…
On the other hand, where game theory says some choice is arbitrary, the brain can have a default encoded - and that default will be universal across humans.