You're definitely right that sarcasm isn't an HN thing. However I still get seriously worried about the personalities of the programmers here who seem unable to recognise sarcasm.
Lame internet humor tends to grow like kudzu, and the users who post it underestimate how lame it is, as scott_s pointed out well long ago: https://news.ycombinator.com/item?id=7609289. Sarcasm isn't quite the same but it's related.
I do however agree about the kudzu and that it is better to just keep it at zero. The purpose of my two posts here is to better understand the community within which I work, not to argue for HN policy change.