I love chocolate sorbet, but I don't want chocolate sorbet on my pants. I feel the same way about empty jokes in discussion threads.

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.

I think the lack of information (conversely, the increase in noise) is what is being downvoted. It is possible, although much more difficult, to be both funny and informative.

That being said, it cracks me up when people get downvoted so heavily for jokes!

yeah. :-)

once in a while my attempts at humor somehow dodge down voting, but not this time. tough crowd. tough crowd.

It's very tough out there on the HN comedy circuit. Exhibit A - https://news.ycombinator.com/item?id=16633615