I don't know man, maybe I'm wrong. I've been using HN for over a decade now, I've found constructive criticism to be a huge part of the positive culture here. It can of course be selection bias as I try to read more of that stuff and collapse a thread as soon as it gets into less constructive direction.
But on the other hand, this is what the guidelines say
> Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something.
I don't think these type of comments teach us anything. But these are guidelines and not rules for a reason.