This letter reads hollow and I've seen a number of them before. If everyone operated this way OSS would be an apocalyptic nightmare.
I'm also not really sure what the author expected here. Having popular stuff garners unfair criticism. It's part of the gig. You can't control it. It feels like a rant - I understand, completely - but when you send people to a specific comment and tell them "see what this asshole said about me!" you're sending emotionally charged people behind the defense of their computer screen to gang up on that person. It's no longer an example, it's an abuse of power. And it feels like the author knows this, given they felt the need to write an announcement article.
This feels incredibly poor taste.