Yes, it is a common clickbait tactic. Also, rhetorical questions, by definition, don't get answered. If it's rhetorical then the article content is pointless? I don't see why this bothers you all. Saved me a click so I appreciate the comment.
True, but most people will have clicked through to the HN comments without reading the actual article. So I suppose it's helpful for the comments to give a succinct answer to the question for the people who don't know.