HN is very focused on interesting topics and polite discussions.
I'm constantly learning new little things here, also I already bought ~10 books based on local recommendations.
I don't view HN as a waste of time at all
There is a lot of threads like "recommend books". I've bought DOOM and Wolfenstein 3D black books (excellent reads!), books on Commodore and Amiga history, Helen Custer's Windows NT book (excellent as well!) and some others.