Could you explain why it is standard practice to downvote jokes? I don't get it. If it's funny, then people might want to read it. Over on /. a lot of the best comments are modded funny.
It's tradition on HN, in an attempt to lower the chaff and keep things on-topic. It used to be that any attempt at humour would get you canned, but now it seems the pendulum has swung to 'if there's no other content in the comment'. The same goes for comments about people not being able to handle things like in your edit - they don't really contribute anything. Snark is frowned upon.
I don't think pure jokes automatically get downvoted, if they're funny enough, though I have no recent examples in mind. But this particular example is more condescending than funny.
Jokes beget worse jokes beget bad jokes, until the majority of the comments consists of people trying to be funny and it's hard to judge insightful comments. That's my major gripe with /. and Reddit.
Thank you for letting me know it was one. I wouldn't have realized I needed to downvote this.