On the source of ethics/norms/morality (including “property”) from Hayek on Spontaneous Order and Constitutional Design by Boykin posted in this thread recently:
“Hayek contends that cultural evolution proceeds through a group selection process in which rules conducing to productivity spread at the expense of less-efficient practices. A group that observes better-adapted rules can support a larger population, so its practices displace other practices as it grows and as members of competing groups adopt these more effective behaviors.”
It seems the answer is as simple as: The societies practicing the “Kill whom/whenever you can” norm – to the extent that they ever existed – are simply not around to tell the story and compete in the evolutionary “market” of property norms. The rare remnants of such societies within us are the mere appendix of humanity biding their time before societal evolution eradicates them completely.