These are the same people (I believe) who discusses post on Reddit or Twitter. I'd rather think that it is because UX, algorithms or other thing which is not related to whether locals are into or not into discussions.
HN is designed to encourage news over discussions. PG thought free discussion would encourage "blogging" and low quality content.
Which is why the text of those posts is pre-faded, so the longer they are, the more painful they are to read, and the less likely they are to be engaged with. News posts also get more visibility than text posts.
Which is why the text of those posts is pre-faded, so the longer they are, the more painful they are to read, and the less likely they are to be engaged with. News posts also get more visibility than text posts.