surge on May 2, 2016 | root | parent | next [–]
The default sub-reddit's turn into what happens when you have a site populated mostly by the lowest common denominator and posts that appeal to the same. Once it became mainstream the defaults just fell into an Eternal September cycle (https://en.wikipedia.org/wiki/Eternal_September) that most sites never recover from. However, reddit had a defense mechanism against this in that there are many, many subsections and almost hidden communities or "True*" sub-reddit's for the core/original users who prefer some semblance of thought provoking content or discussion, or at least pretend to.
I generally unsubscribe from all of those defaults (except maybe /r/WorldNews) and almost never look at them, have some lists of subject related sub-reddits I like (ex: tech). There are sub-reddits that have communities in them I haven't found a replacement for elsewhere aside from maybe some private FB groups. There is something to be said for exclusivity or staying obscure. For every /r/The_Donald there is a /r/Sweden, or for /r/SRS and /r/RedPill there is /r/TwoXChromosomes and /r/AskMen. You aren't going to read about the good communities in the news, as polite people having interesting level headed discussions rarely makes headlines.
To me Hacker News is just another sub-reddit like site. I usually see the same links posted in my sub-reddit's as I do HN, and I'd wager the discussion is sometimes better in the sub-reddit's than it is here, it's at least on par.