Why doesn't HN allow to delete our posts?

I've noticed that HN is pretty much the odd and unique one out here. Almost every major social network I know let's you delete or edit even a five or ten year old post. But HN posts are like carved in the stone and Frozen in time?

Whatever maybe the motivations for it, it's a bit authoritarian in the sense that the user isn't in control of her own data. Pretty sure RMS wouldn't like it even though it checks most of the other GNU boxes I think!