I run showdead, and most shadowbanned accounts deserve it. I also rescue the occasional comment from the grave.
Do the moderators un-shadowban users if they get enough vouched comments? No idea, but they do have enough information to do so.
When I run across such an account, should I email an HN mod to investigate? I wouldn't mind doing that, but I've tried before and never got a reply back -- so not sure what the outcome was.
It's stupid as fuck. Reddit is also plagued by it.
Emailing a mod can't hurt, though.
Self-hosting is better, I agree, but people use medium, github, twitter, youtube etc because they'll instantly have a much bigger audience. I mean a self-hosted github alternative should be easy to set up on your own servers.
Actually if you operate a JS library with things like a CDN and hosted icons, you probably should. Sure, github is free for things like that, but you - and your users who depend on you - cannot depend on them.