I think you are right, I had a weird feeling about my comment while writing it and I felt I was missing something. I don't think I'm wrong however. Perhaps it is that readers of hackernews are more in touch with certain things than the general public. I read HN specifically to avoid the noise and nonsense of the sources you named, for example.
That doesn't mean I only want to read tech news or things of "intellectual curiosity", it just means that the news sources the two organizations you named draw upon are in the business of publishing garbage. The up/down moderation and flagging of a real aggregate site like HN makes a huge difference in quality of content, when it's used properly. Reddit users abuse it to vote their feelings which defeats the benefits.
The thing is, the readers HackerNews attracts are a result of its focus; weakening the focus invites HN gaining the character of the sites you don't like (some of which, as you note, have similar community moderation mechanisms bit different results, compared to HN.)
That doesn't mean I only want to read tech news or things of "intellectual curiosity", it just means that the news sources the two organizations you named draw upon are in the business of publishing garbage. The up/down moderation and flagging of a real aggregate site like HN makes a huge difference in quality of content, when it's used properly. Reddit users abuse it to vote their feelings which defeats the benefits.