I think there's no point in discussing this on the mailing list, as it's off off-topic (and the topic seems mostly closed).

On Tue, Feb 20, 2024, at 1:21 AM, Dmitry Gutov wrote:
On 19/02/2024 21:47, Bozhidar Batsov wrote:
> My memory is fuzzy as well, but I recall some sparks here 
https://lists.gnu.org/archive/html/emacs-devel/2013-12/msg00552.html 
> <https://lists.gnu.org/archive/html/emacs-devel/2013-12/msg00552.html> I 
> also vaguely recall that he didn't like the vibe of a part of the Emacs 
> community and this was a factor in his ultimate decision to quit Emacs. 
> It's a pity - for me he was a really great Elisp hacker and package 
> maintainer.

But I'm not seeing the "attacks" here still. If the discussion is tense 
after he both states Flycheck's strict superiority and his firm decision 
never to contribute to Emacs, well, that's kind of expected.

But not to the extent that could explain the phrasing in his subsequent 
blog post (now long removed). I was puzzled; he never responded to my 
comments then. And yes, he's pretty great hacker, so it's all quite sad.