People use the word "censor" in many different ways that it's not always clear what they mean by it.

We don't moderate HN comments because of the views they express; we moderate for comment quality and adherence to the site guidelines. In the vast majority of cases where we moderate a comment, it's not because of the view it expresses, but because it expressed it in a way that's destructive of the culture we want here (https://news.ycombinator.com/newsguidelines.html). You can call that censorship if you like, but I don't think it's what the word classically means. In most cases there are other commenters expressing the same view thoughtfully and substantively, and those comments don't get moderated at all. I think we can say after 10+ years of working with this strategy that it definitely isn't "the shortest way to the bottom" - quite the opposite.