Not that it's a bad thing in any way, but the title of "hacker news" is a bit disingenuous when "developer news" might be a little more accurate. I wish I could filter out the programming and startup stuff.
My opinion wasn't so much about what would replace those posts, but what not having those posts would attract.
I suppose for example /r/gamedev isn't awful, but really, GameDev.net is much bigger and better. There's little reason to bother with Reddit.