Post hoc, it can be said that the decision was for the goal of social harmony for the community (because post hoc, the community consists only of people who benefited from the decision). — Isaac

Yes, it seems reasonable to think that it would be a majority community decision, and that the perceived benefit of the majority would be the driver of such decisions.

It seems that you want to exempt (or set aside perhaps?) the act of determining the in/out status of people from moral judgement. — Isaac

Moral judgements of such decisions could only come from outside the community in question, from some larger community perhaps. If we take a global perspective then we could ( purport to, at least) judge otsracizations from the perspective of humanity as such, I suppose.

In any case I have been more interested in the functional social purpose of mores, and I remain convinced that the general function of mores is to establish and maintain social harmony within the various communities within which diverse mores are to be encountered.

I am not denying that in some, usually more authoritarian, communities there are idiosyncratic mores which may be designed, or at least serve, to dis-empower classes of people. We may (purportedly at least) judge these from a larger perspective of humanity. If not from that posited perspective, then what?

We see 'rights' through the lens of our culture. — Isaac

I agree with that. But the salient point is, in my view, that the very notion of universal rights is based on the rational principle of lack of bias, prejudice and privilege, and we have become a rationalist culture at least in the "thinking sphere" (and in theory if not in practice), for better or for worse. What could you imagine would be a viable alternative? Not embedded traditional or religious values, and not merely personal opinion, surely?

RICHARD DAWKINS: I very much hope that we don't revert to the idea of survival of the fittest in planning our politics and our values and our way of life. I have often said that I am a passionate Darwinian when it comes to explaining why we exist. It's undoubtedly the reason why we're here and why all living things are here. But to live our lives in a Darwinian way, to make a society a Darwinian society, that would be a very unpleasant sort of society in which to live. It would be a sort of Thatcherite society and we want to - I mean, in a way, I feel that one of the reasons for learning about Darwinian evolution is as an object lesson in how not to set up our values and social lives.

I think he missed the point by a long shot. Societies survive which are fit to survive, and humans survive which are fit to survive. "Fittest" is not a pinnacle at which one and only one specimen exists; "fittest" could be a group in which there are varying degrees of "fit".

Humans survive in human societies because they attain a level of fitness that is needed for survival.