Sites like HN can't escape Parkinson's law of triviality: Complex or mixed-conclusion content will naturally get drown out by easily "understood" (at least in the perception of the reader) and debated material.

Titles play a large part as well, as they allow people to support or reject a notion without the effort of even following the link.

This isn't meant to be grumpy or conspiratorial, nor is it negative about HN, it's just the way these things often work. HN does not measure or demand that you follow a link to click the arrow (nor does it require it for "flag", which is a used in practice to downvote). It doesn't maintain a history of recently visited items to ease voting on content you may have read earlier in the day. These naturally lend themselves to cheap votes.