You shouldn't use HN as a place to gain knowledge itself; Google is much more useful for that. HN is best seen as a place to expand one's awareness of knowledge.
For example, people here have provided their thoughts on "security through obscurity" -- a clear controversy exists! Your next task would be to Google the phrase, and read the Wikipedia article[1] that comes up. Then, if you still have questions, check out the references the Wikipedia article cites[2][3][4][5], or perhaps visit other results from your Google search[6][7][8].
In other words, Internet social media sites are terrible places to learn -- use the greater web to do actual learning. Use social media sites like HN and Reddit to expand your awareness of ideas.