Please don't take HN threads on ideological tangents. The point you're making has by now become well-known ideological flamebait. We ban users who derail HN threads in such directions, so please don't.

https://news.ycombinator.com/newsguidelines.html

Edit: since https://news.ycombinator.com/item?id=16063749 makes it clear that you're using HN for that purpose, which is not allowed here, I've banned this account. Would you please not create accounts to break the site guidelines with?

Why?

More diverse population—> lower trust —> less social will to support each other.

So we should be tribal societies, then? (I.e., endogamous. As in cousin marriage.)