The spam died off because Usenet died off. If users ever went back to Usenet, the spam would come back again behind them. There's nothing in the design of Usenet that can stop spammers from spamming.
(There wasn't anything back in the '90s in the design of email to stop spammers from spamming, either; but enough people cared enough about email that billions were spent to add that spam-proofing. Nobody cared enough about Usenet to invest a similar amount, so it's still as unprotected as it was when Monica Lewinsky was in the news.)
(There wasn't anything back in the '90s in the design of email to stop spammers from spamming, either; but enough people cared enough about email that billions were spent to add that spam-proofing. Nobody cared enough about Usenet to invest a similar amount, so it's still as unprotected as it was when Monica Lewinsky was in the news.)