I couldn't agree more, on both counts. It's such a thrill seeing a link to a research paper or exceptionally well written essay, and have the author answering questions in the comments. I can't even estimate how much general science, history, and literary education I've received this way, almost by accident. No doubt I am a much more well rounded person as a result.
I rarely read TFA. I'm here for the discussion, and if the discussion is extraordinarily interesting, I'll read the article for clarification. To me, HN is the "guild" that teaches fundamentals, and keeps me abreast of the state of the industry (and many, many unrelated topics that are equally interesting!). Normally this level of access to illuminating dialog would be restricted to universities, but I can get it here for free, in my underwear. I've spent a good part of my life geographically isolated from centers of learning and industry, and being able to remain in the loop is priceless. I doubt my personal and professional growth over the last 10 years would be a fraction of what it is if I hadn't had this resource. Yes, I am a fanboy.