The important thing to note about Erik's behavior is that occurred on Usenet, and unlike the mailing list or places like HN, on Usenet, there were (I have not looked closely at Usenet for about 12 years) no "owners" or moderators for a newsgroup and no way for the newsgroup considered as a "community" or a "collective" to enforce behavioral norms (e.g., around politeness) on individual posters.
Individuals regularly complained about Erik's nastiness, saying (correctly, IMHO) that he was scaring people away from Lisp.
Also, I never saw any of the intense admiration for Erik on comp.lang.lisp when Erik was alive that I have seen on Hacker News. The quality of his Lisp code and the insightfulness of his posts won him respect from many on comp.lang.lisp (specifically, those who accepted that there were almost no limits on speech on Usenet), but he would definitely not have been tolerated for long in most places on the internet where technical subjects are seriously discussed today (particularly HN, which has higher politeness bars than most such places) if he were posting with the same hostility that he did on comp.lang.lisp.
All good points, but I would debate about whether newsgroups would not be considered a "community". A few I'd been involved in in (lord, so many...) years past certainly had all the hallmarks of one. c.l.l was large enough to have perhaps diluted that, but the lack of an owner I don't think is necessary.
But yes, those were different days in different contexts.
Individuals regularly complained about Erik's nastiness, saying (correctly, IMHO) that he was scaring people away from Lisp.
Also, I never saw any of the intense admiration for Erik on comp.lang.lisp when Erik was alive that I have seen on Hacker News. The quality of his Lisp code and the insightfulness of his posts won him respect from many on comp.lang.lisp (specifically, those who accepted that there were almost no limits on speech on Usenet), but he would definitely not have been tolerated for long in most places on the internet where technical subjects are seriously discussed today (particularly HN, which has higher politeness bars than most such places) if he were posting with the same hostility that he did on comp.lang.lisp.