I don't know what you mean by "no value outside of to YC" but I think—in fact I know—that HN has added massive value to lots of people's lives, and not just by providing interesting reading material. I know this because people tell me how HN changed their life, and I also know that HN changed my life (long before I started as a mod).
But I'm members of other communities that always have at least 100-200 people online at the same time. I guess that is still a fraction of HN? But They all work well.