Snark is frowned upon on Hacker News. It's generally low in signal and often drags the tone of the conversation down, so it's part of HN culture to downvote snarky comments.
I've noticed that with comments of my own - where I've made a sarcastic comment, then said 'kidding aside now, real comment' and been heavily downmodded. Normally this wouldn't rankle, but in the same threads are far more sarcastic comments with zero content happily getting modded up, sometimes quite strongly.
Another time I was arguing against a guy about language, and despite his position being offered in good faith and with a degree of detail in his argument, he was modded into the negs.
Comments do seem to do better here when appealing to emotion and popularity rather than internal merit.
