Can you articulate the ways in which it seems not-a-social-network to you?
Comparison with reddit might be useful.
The only fundamental distinction I can draw is that there's no unified source of identity in usenet. All the rest of the differences come down to moderation policies.
I consider something a social network when it is designed to create and make use of a graph of relationships between people. This is distinct from social media, though we use the two interchangeably a lot of the time. The "network" part is about the graph of relationships, the "social" part is about people (and not servers, as I suppose is the case with Usenet).
I'm not sure about Reddit, I don't use it often, but if you can only follow forums and not people, I would not call it a social network either.
"Social media" to me refers only to services owned and controlled by a corporation (or maybe a non-profit organization similar to how the Guardian newpaper is owned by a non-profit) and targeted at average consumers, not just techies. Although there have been corporations (e.g., ISPs, Clarinet, Deja News) involved with Usenet, no one (corporation, organization, person) has ever owned or controlled Usenet. "The Big-8 board is the closest thing it has to a central governing authority," says the OP, but it has only a tiny fraction of the level of control over Usenet that, e.g., Reddit, Inc, has over Reddit.
Before the rise of the web, Usenet definitely was the front page of the internet, though--to a greater degree than Reddit ever was.
Part of the nostalgia for Usenet I think is nostalgia for a time when corporations had very little influence on the internet. Although most of the people running Usenet (and maintaining Usenet software) in the 1980s and early 1990s were involved with software and the Internet as part of their job, running Usenet was not part of their job description.
IRC and the first massively-multiplayer online games (which were text-only and called MUDs) were the same way.
Till the early 1990s the US government paid most of the bills for running the internet, but used its influence very sparingly: there was a rule against commercial activity (which I think was motivated by appeasing commercial interests worried that the internet would compete with their services) and there were attempts made to make it less likely that the internet would get criticized by Congresspersons and journalists as an expensive waste of money: e.g., Jerry Pournelle's getting kicked off MIT's terminal servers circa 1985 out of fear that he would be careless in how he would write about the internet. And that is the extent of the rules imposed by the US gov that I know about.
I think early on, there was no front page of the internet. It would have been your university's telnet or gopher server or something. But really there wasn't one. I don't think it was Usenet, certainly. With the early web, Yahoo might have been the closest thing. I don't think there could be anything like centralization or aggregation (I mean: a single place people went to by default) until the browser became ubiquitous, which in my personal history marks the end of the beginning, or the beginning of the middle phase of the internet. I agree that many people spent a lot of time on Usenet, but I think many more people couldn't be bothered.
I learned basic scripting by writing rooms and content for MUDs, I love them and sometimes wistfully think about starting one up.
> designed to create and make use of a graph of relationships between people.
I assert that a universe of people maintaining killfiles is exactly this. It is the default-trust map of social network, in which one imagines that the exceptional cases are those whom one wishes to shun.
I think a requirement that one be able to "follow a person", that is to say watch all the things that individual says, is excessive. We're getting down into the weeds here, but I think following topics and threads are much more useful than following humans.
What was more useful wasn't the question. Social network and social media emerged 20 years ago when people needed a name for following humans.
Usenet was not designed for kill files. Kill files were designed for Usenet. You could construct a very limited social graph from everyone's kill files. But no one had everyone's kill files. And you could construct a limited social graph from everyone's tax records also. Are taxes a social network?
Moderation policies matter a lot. The tech behind Usenet makes moderation much more costly than it is on anything commonly called a social network (and the people running Usenet are opposed to moderation of anything other than outright spam or so that's how it always was when I stopped paying attention about 15 years ago).
I agree that moderation policies are important. But I think it's missing a point to decide that "A social network with bad moderation policies" is therefore not a social network.
Easy comparison: Mastadon has distributed identity, and localized management of moderation. Is this sufficient that we should deem it "not a social network"? I think not.
I think there was no real consensus in USENET towards the appropriate degree of moderation, rather several standing waves of opinion. All the species of technically simple moderation patterns were present there: A species of subscriber,
or every message approved (basically only a radically small set of approved posters) and so on. Since some of the newsgroups are functionally archives of mailing lists, there's a whole additional universe of moderation techniques applied "upstream".
>All the species of technically simple moderation patterns were present there
I consider voting (allowing readers to upvote and downvote, which is extremely quick and easy compared to writing a comment) an important technically simple moderation pattern, and I'd be very surprised to learn the voting on Usenet articles was ever possible.
>Mastadon has distributed identity, and localized management of moderation. Is this sufficient that we should deem it "not a social network"? I think not.
Good point. Something created for the explicit purpose of competing with (in the sense of taking users away from) a social network should be called a social network.
Comparison with reddit might be useful.
The only fundamental distinction I can draw is that there's no unified source of identity in usenet. All the rest of the differences come down to moderation policies.