HN is not a monoculture the appropriate stuff on the site can interested anyone and no one is required to be a software developer to get on this website.
Nobody is required to be anything on any public forum; that doesn’t change the fact that communities exist, and the vast majority of people on a forum are there due a particular taste, and share a common preference for discussion.
That anyone of any interest can visit the webpage is not a sufficient explanation as to why anyone of any interest do visit it. The question is whats so special about HN that draws such a varied background, despite it clearly having its strongest preference towards software engineering (on any given day, if you counted by category, it would be surprising to find software engineering / programming not as the highest).
A reddit forum has the same public property, but the software engineering channels presumably do not draw such varied backgrounds. So why?
Maybe granularity -- there's only one front page for HN? I usually find that I want to read 10% of articles on the front page, but I'm often surprised by which 10%.
