I support Hacker News moderating itself however it chooses. However, if we are looking at it as a moderation model for large, open, non-editorial platforms (Youtube, Facebook) -- which I believe should all be covered under public accommodation law -- it clearly fails. And even if when we are looking at ostensibly neutral, publicly-orientated sites like newspaper comment boards, it fails.
Hacker News moderation is not appealable, not auditable, does not have bright line rules, and there are no due process rights. It simply does not respect individual rights.
So while this moderation method succeeds for Hacker News, and perhaps should become the model for small private sites, we should not try to scale it internet-size companies. Platform companies (Google, Facebook, Twitter) and backbone companies (ISPs, Cloudflare!) need a different set of rules geared towards protecting individual rights and freedoms instead of protecting a community.
The backbone companies thing is the more important point you make imho, and is why discussion about what the modern public square really is and how the level of corporate dominance of media and the abuse of third-party doctrine allows the silencing of dissent. So a private company can censor whoever they want right?.. but how far does that go? First it starts with cloudflare, and then eventually it goes down to the ISP level... and that seems like a very dangerous slippery slope to me.