To be fair, we can expect some diversity among several millions of readers from many different countries, points of view and experience in different fields.
If HN had some concept of subreddits, even if it were just a few them, the situation might be different. There are quite a few high-quality subreddits out there with a lot of experts. (I don't know if creating "sub-HNs" is a good idea in general; probably not.)