No definitive answer is forthcoming... more research is needed!!!

Since I love pickles, I love laughing with and at pickles, I am only proposing this alternative theory in order to explore potentially lesser known reasons for pickle funniness. Maybe this could be the "Halton Arp Cosmological Theory of Funny Pickles":

what if they aren't really funny? what if it only appears that people are smiling and laughing but it's really from the sour tangy bitterness making us pucker?