Double standard in bigotry? ?

It is considered taboo (and rightfully so) to produce any sort or comedic ethnic comedy routines or ethic or racial jokes. However, it is perfectly acceptable to make “redneck jokes” or produce comedy based upon the stereotypes of Appalachian or Southern (US) people. Why the double standard? Some Southern and Appalacian comedians have even made money on this double standard (Jeff Foxworthy for example). Frankly I put people like Jeff Foxworthy in the same category as Stepin Fetchit.