HN is fairly intolerant of any kind of humor, I've found (unless it's the snarky kind). I've been downvoted more than once for trying to crack a joke, in fact I don't even forsee this post faring well, even though it's an attempt to inform someone else of a valid point.
Of course, making a comment like that seems to correlate with the downvotes not happening. Perhaps meta-complaining is like the Windows Rule.. every other level of complaint is spared the downvotes.