It's strange.
There are many things in the arts that seem to translate across cultures. Well, perhaps not "many", but quite a few.
However, in performance arts, these sorts of things seem to be more culturally focused. Comedy does not always translate well across national boundaries and given certain cultural/social differences.
So, a comedian who may be considered much beloved and brilliant in one country/culture, may be a mystery to another. Yet, some performance arts like acting, which many comedians pursue, music and then the physical performance arts, like ballet, acrobatics, etc... these translate more surely across cultures to be more widely appreciated.
I suppose its that comedy is nuanced, often serving to illuminate the human condition the audience experiences and, often, serves up political and social commentary. So.... a lot of comedy could contain things that just aren't found in other cultures. For this reason, IMO, comedians are generally culturally localized except in certain sorts of shticks/genres that can easily translate. And... they don't generally push across cultural bounds, since it's recognized they'll not likely find a lot of success or too much competition that is more culturally acceptable...
AND... You can be assured Rickles woudl have ripped me a new one for being a complete boor. And, take my word for it, I would have laughed.
