Those comments he linked to did contain actual arguments. They also contained insults, which is unfortunate, but they were definitely not merely ad hominems.

I would not have problems with such comments directed at myself. As long as there are well written, structured arguments in there a insult won’t annoy me. Well, it probably will, but not very much.

I think it‘s also important to note that this is a controversial, highly emotional topic. I would expect it to get a little bit rough whenever that’s the case. The vast majority of comments on HN don’t contain insults or ad hominems.