If there's one critique that I believe is paramount it's that HN has, due to its readership, an ethical obligation that goes beyond making discussions all nice and civil.
Political issues are obviously divisive and it's perfectly fine to keep stuff like the El Paso massacre of the front page. But when hot-button issues intersect with technology, the HN readership is in a position of power, and shouldn't routinely be spared the anguish of being reminded of their responsibility.
Yes, articles about, for example, discriminatory ML do often make it to the front page. But in my impression, that topic (as well as employment discrimination, culture-wars-adjacent scandals in tech academia etc) are far more likely to be quickly flagged into oblivion than similarly political takes that just happen to be in line with HN's prevailing attitude (e.g. cloudflare-shouldnt-ban-<x>).
The article impressively articulates what toll divisiveness takes on the moderators: Even if I read the same ugly comments, I am unlikely to experience the sharpness of emotion that apparently comes with considering the community one's baby, and making it's failures one's own. When such divisiveness is then reflected in the "real world" of mass media, the pressure only increases.
But as this article shows, abdicating the responsibility by keeping the topics sterile is similarly suspect, in the sense of fiddling while Rome burns. I believe a willingness to confront the ugly sides of technology with some courage of conviction would eventually be recognised, even if it may occasionally involve a bit of a mess.
I find this the crux of the issue at large, there is no such thing as "no problems".
Therefore, what was the point of this criticism in the first place? (in the article, not your comment)
It seems to me, the author didn't like that HN actually allows open discussion and respectful (mostly) sharing of opposing views.