That makes sense. HN is larger than people usually assume—it gets about 5M monthly readers. In such a big population there are subsets who take any point of view, and on divisive topics the ones who tend to comment a lot online tend to... skew to the tails, shall we say. The vast majority just don't say anything. Since there is almost nothing to stop people from posting whatever they want, we get a wild set of initial conditions. You should see some of the content we have to deal with before you run across it (or rather, I hope you don't). There are good-citizen users who help us with this a lot.
It takes moderation to react to that and settle into some community norm. HN does have relatively cohesive community norms, but with so large and open and online a community, such norms can never be more than a statistical cloud, with large outlier regions. This is why I tend to react when people draw conclusions about the community from particular posts that appear—it leads to misleading conclusions. A better thing to draw conclusions from would be the flagging behavior, but this is harder to observe and takes time to show up.
Edit: There's another factor which is poorly understood, and which I think might have been at play in the comment you were reacting to above: HN is a highly international community. Norms on divisive issues vary greatly across countries. Many of us tend to assume that HN is composed of people mostly like ourselves (in terms of background), but that's far from true. After observing the data closely for many years, I'm convinced that many international differences come across as outrageous domestic behavior when we misinterpret who's speaking. Not that a statement would be more acceptable, necessarily, if we knew—but it would be less provocative, because people seem willing to adjust for this when encountering opposing views.