I don't think you're being fair to the community here. It's true that such comments exist, and so do many other kinds. Many users share personal experiences. Many express vulnerability. Self-doubt, questions, and comments expanding on others' ideas are highly represented here, and we value them tremendously.
I puzzled for years over why people would say things like "90%+ of all comments" that are so obviously (to me) untrue. But now I think I know why: those kinds of comments stand out more. It is as if they burn a deeper impression into the brain of the reader, usually a more painful one, so one comes to feel like they're "90%+" even when they are not. This perceptual loop is hard to break out of, so I've begun to see it as part of the moderator's job to inject new information when people post like this, in the hope of opening the loop back up. It's important for the community to see the good in itself and not just the bad. Otherwise why bother to take care of it?
HN has problems with disrespect, incivility, aggression, but one must evaluate this from multiple sides. Every large, public, anonymous place on the internet has this problem, usually worse than HN does. The problem is systemic, but that doesn't make it hopeless, it just makes improvement slow.
Every HN reader I've met has a love-hate relationship with the site. There's something deep in that, and a lot to say about it, but here's one that gets back to the topic of this thread. In my opinion, the aggressive dynamics of open internet argumentation relate to the gender dynamics of what tends to make women feel more or less welcome in a place. An atmosphere of hostility—or anything above a certain toxic baseline—causes many people to want nothing to do with a place or to feel deep ambivalence about it. I have that reaction myself, and my sense is that women tend to have it more than men do. This is what came to my mind when Cadran wrote that she started Leap because she doesn't feel welcome in "shouting matches".