I brought up Cliparr because someone was being pre-emptively called a slop merchant before anyone had looked at their code. You don’t have to be personally involved to think that’s worth pushing back on.
On the catalyst: you’ve characterised it as “a single negative interaction and a handful of downvotes.” You’ve also already acknowledged you missed the deleted posts. Those two things are doing quite a bit of work together. The comment that preceded the edit wasn’t a downvote - it was being told I was “fluent in slop”, and that my app might kill someone, directed at someone who is autistic. That’s the interaction we’re talking about.
I’ll take the broader point that the phrasing was undiplomatic. But “perhaps you should reexamine how you handle criticism” is a bit rich from someone who’s called me a twat twice and is now on their third comment about it.