[dredmorbius]

A significant part of the culture was that Usenet was tied, almost exclusively, to selective-admission universities (and largely CompSci / EE students and faculty), a few high-tech companies (infotech and defence, largely), and a few government departments. Those institutions could exert reasonable disciplinary control over Usenet participants ... enough to avoid the grosser harms.

Yes, it was highly exclusive and exclusionary, and there were definitely toxic elements to the culture, but it wasn't entirely lacking in control or discipline as occurred later.

Note that Usenet did have some effective spam controls ("Cancelmoose", the Lumber Cabal, etc.), but overall effectiveness was limited by virtue of the distributed and noncentralised nature of the protocol, as well as the lack of any true participant authentication.

Slashdot was harshing on Usenet long before Reddit was, and various online forums (as you mention) before that.