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.

The HNers for Humor Coalition wishes you well. From both of us.

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.

the joke is tolerable if it adds something to the discussion or helps me learn something i didn't already know.

for me, HN is the reference section of the library. it is not that it can't have humor, it should be useful for more than just a laugh.