While agree fully with your point that we should not judge things by the medium they are using, I cannot fail to see how most of the comments violate the guidelines of HN (take my comments with a grain of salt, I used google translate to look at ~10 conversations).

1) There is no karma system so there is no ranking based on quality. You can say that the number of likes can be considered as karma, but that does not rank comments or links.

2) Though people there can be considered civil, not all of the comments are particularly interesting. I come to HN as 80% of the conversations make me go "OMG, I never thought of it that way". That didn't happen here. But again I just looked at a small sample.

3) I don't care how many members you have, you may have 10 or 10,000 the question is, how many of them are actively contributing at least mediocre quality content. Judging by the profile pics I see, it cannot by more than 40 and that too is a conservative count.