Ech, down-voted for humor. Sometimes I wonder if the HN crowd has a minority contingency of hunchbacks licking salt and sucking on dewy moss for sustenance.
If you are contributing to the conversation, your joke will probably get upvoted for the insight it brings. If your joke doesn't contribute to the conversation (e.g. the joke above was just a pun), it will rightly get downvoted because that's what you're supposed to do with comments that don't contribute to the conversation.
There are lots of other places on the Internet we can go for jokes — most forums, actually — so I think it's OK for some places to try to push for a higher signal-to-noise ratio.
That being said, it cracks me up when people get downvoted so heavily for jokes!
once in a while my attempts at humor somehow dodge down voting, but not this time. tough crowd. tough crowd.