Visit Parts of London, Hull, LeeRAB, Manchester, Liverpool, Birmingham, Nottingham and you will see a different view. Just because LA is bad, it doesn't mean that all major American cities are.
A gag about eating cockroaches would last a few minutes at best, a gag about a guy pretending to be a black man as part of over doing the method method acting has a number of gags which can last a whole film - your analysis implies that the whiteman-as-a-blackman gag is a one trick pony.