In the days when crackpots wrote in text-only media where no normies tread, they were probably somewhat cognizant that their audience invariably saw straight through their non-sense. Therefore I imagine a hint of tacit self-deprecating irony was an essential part of all USENET crackpottery. E.g., set theory cranks would claim to have shown Cantor's work to be a fraud, and yet while comparing their persecution to that of Galileo, they would do so with a twinkle in their eye.
Unfortunately, this sense of humor no longer becomes a requirement when you have an audience that literally believes even the absolute dumbest things you could possibly write (don't get me wrong, these people posted on USENET too*, although usually their tldr.txt would be easily recognized as spam, and hopefully with their authors ending up in people's killfiles).
*Incidentally, since Google has taken over USENET as Google Groups, these seem to be the only remaining people that post there. Quite possibly because their completely borked and lard ass web UI is so broken beyond all hope of usability that nobody would ever use Google Groups for anything anymore except for mailing out p3n15 pill adverts