In honesty, reddit doesn't attract a lot of the actually-hacking hacker crowd.
I go to reddit to see what consumers think and HN to see what producers think.
Reddit is more like an unbridled 'id' of people in a similar culture to HN. Witchhunts, trolling, nastiness, low-effort posting, are stereotypes of reddits most famous and popular areas, and for good reason. Almost every community of any size on reddit is a pretty intellectually barren place (shout out to the outliers like /r/askscience).
It is what it is, but you go to reddit to talk about video games and popular culture and cat pictures, and you go to HN to talk about coding, web development, and the many topics surrounding it.