HN is largely a tech site geared toward mid-late twenties individuals (the start-up culture, really). Reddit is a social network geared toward late teens to mid twenties (males). Yes, there is overlap, but not to a significant degree.
Uh... you know that there are vast VAST circles of "startup culture" that are much older than late-teens/mid-late twenties.
Where the heck do you think fucking silicon valley came from - you think all the people who built all this stuff are dead, gone and not connected to the pulse of technology?
so, I assume you're quite young - but may have a poor understanding of tech history. All the +30 people are still here.
But when I say "start up culture" I basically mean "silicon valley startup culture" and HN is basically that and its fan club. Mostly the latter. It is the difference between being part of "the gig economy" and just a part time/contract worker.
Yeah, there are some older people around here, just like there are at reddit and the like. But just reading and engaging in threads, it is very clear that this also skews pretty young.
And a large part of it is that the people who are in their 30s and beyond tend to either not have time to hang out on a message board and discuss things with kids in college (in my defense, I am between projects and killing time).
I know that as I grow older (I am 41, working in tech my entire life) I lurk a lot more and more.
I am top mod of a subreddit of ~400K subscribers... I participate less and less as I get older - even if I have really strong opinions, I tend to just sigh and let the younger gen mods deal with it...
vocal minority and all that...
Someone will one day do a thesis on this phenom and put a name to it