alt Hacker NewsHow would any new user earn karma in that system? How would any story get upvoted?
Again, this system can only work if there are at least _some_ people that are willing to upvote newbies and read new posts.
It sounds like what you want isn't a community with collaborative filtering, like Hacker News, but a newsletter with editors, like Slashdot for example.
People will need to participate otherwise there won't be any new content. I see it as just like vouching, except someone has to vouch for green accounts. A slightly more equitable (and easier to implement) version of lobste.rs' invite tree.
What I want is for green accounts not to be abused as much as they are. The number of noxious, vitriolic troll alt accounts and bots is getting ridiculous. That is almost entirely the fault of established users of course, but there's no way to deal with them poisoning the well without affecting new users.