Topics do trend, and the various camps will quickly rush to author and promote things that conform with their worldview. Users will search for correlating content to submit.
But to address something that is a personal peeve -
"And from the author's perspective, whether they are writing it to take advantage of the opportunity for increased page-views."
Much of the content that we see on here are people writing about topics that motivate them. If they saw a post that they think is wrong and they want to refute it, or if they think it is right and want to add supporting commentary, they author posts to support their position.
The majority of these posts have no ads, which is good because it is catering to a market that overwhelmingly runs ad blockers. There is close to zero retention or residual value for audiences like HN: people click to your post, maybe read it (if that), and for the overwhelming majority that is the entirety of the relationship with the author.
You don't shoot to the tops of the blogosphere. You don't rake in those fat Adsense dollars. You get a momentary period in the sun to evangelize some beliefs.