He's referencing an infamous c.l.l thread where pjb wrote some code that would delete all files in your hard drive.[1]
I find it silly to disregard a whole family of languages over a well-known nuisance on c.l.l, but I do not blame the poster. The proverb "one rotten apple spoils the bunch" comes to mind. In any case, this isn't the only place where pjb was simply toxic and encouraging people to stay away from a community or programming language. There is another infamous post of his on comp.lang.objective-c that is simply rude, no way to justify it.[2]
It wasn’t just pjb though. Even on the linked thread you can see another regular, not quite defending pjb for trying to wipe someone’s hard drive, being rude to the new user. And of course the name Erik Naggum is infamous.
I don’t know what the state of the community is these days, and I don’t know if a toxic community alone is a good reason to avoid a tool if it’s best-in-class. But the Lisp community definitely had a problem back then.
I don't think the "Lisp community" generally had a problem. What you remember was on an unmoderated Usenet group and by two people. Usenet was mostly unmoderated. What that means can everyday be experienced on 4Chan, 8chan, Twitter, Telegram, certain subreddits and other current social media channels - just in a million times amplified way.
Hackernews, btw. is moderated and posts/comments can be deleted by the moderators. comp.lang.lisp was not moderated.
The Lisp community at that time was much larger and way more diverse, spread over a lot of communication systems (often via Mailing lists), Universities (US with some other countries joining), R&D institutions and companies. In the very early days Usenet was only used by a small group of people (many Students and Academics), later also there were also personal accounts and private access.
Blaming the "Lisp community" now and then for the toxic behavior of two people on an unmoderated Usenet forum decades ago is not fair. In any large enough group one likely will find toxic people, that should be of no surprise.
I was participating in that Usenet forum and I never liked the toxic behavior of a few people and from the trolls (people poisen the technical discussion just for fun). This created a lot of heated discussions.
I find it silly to disregard a whole family of languages over a well-known nuisance on c.l.l, but I do not blame the poster. The proverb "one rotten apple spoils the bunch" comes to mind. In any case, this isn't the only place where pjb was simply toxic and encouraging people to stay away from a community or programming language. There is another infamous post of his on comp.lang.objective-c that is simply rude, no way to justify it.[2]
[1] https://groups.google.com/g/comp.lang.lisp/c/iKNvssI5pE4
[2] https://groups.google.com/g/comp.lang.objective-c/c/q8Emsjoy...