It was completely genuine. I try to avoid sarcasm on the internet as much as possible, unless it's stupendously obvious, simply for reasons like this.
These days, it seems like people are increasingly uncomfortable disagreeing with each other: "I disagree" is often meant or interpreted as "You're wrong, and you should never have spoken up in the first place, you foolish whelp."
That's why I was really delighted to see a pair of contradictory opinions sharing the top of an HN comment list: it meant, cursorily, that every person who upvoted one did not automatically downvote the other, but also that the community as a whole values the disagreement itself. I know I'm making a mountain out of a molehill now, but only for the purpose of explaining why I wasn't being sarcastic.
Thanks for the clarification! Most people have learned that sarcasm doesn't work in print, hence the <sarcasm> tag, so I assumed it was genuine. It was just such a striking comment - contradictory opinions showing faith in humanity.
