Personally, I think auto-peering would be terrible for the reason I mentioned in my previous post. If you have to manually set up a peer, you have some control over who and what you propagate. If your friend starts posting garbage, one of your other peers might get pissed off enough to de-peer you--which I consider a feature! Configuring a peer isn't difficult, but it does require an explicit human-to-human agreement.
The way things work today, when somebody wants to post on Usenet, they go to eternal-september.org and get a free account. I think something like 50% of postings on text newsgroups must originate from eternal-september, and it's great that they're providing a free service, but things like e-s and the Google Groups Usenet bridge means that there's no accountability for garbage. With a $20 Raspberry Pi, though, you can run a totally capable text groups server, and I think a network like that might have some interesting people on it. It's also a foot in the door toward people hosting their own content rather than shoving everything on some random free online service.