One thing that's likely to attract downvotes are comments to the tune of "+1", "I agree", or in this case, "good one!". The sentiment can be expressed with the little up-arrow next to the comment you like, and then it doesn't clutter up the thread. HN tries to keep a high signal to noise ratio, and part of that is greying out comments that really don't add anything. FWIW, I didn't downvote you, but that's probably the reason that people did.
Now I'm picturing the latest in automobile technology: the Benjabug Franklin! It designs ambitious hats, runs off of lightning, and modifies the timezone it's in dynamically for +/- hours of fun!
