But that isolation has continued by conscious housing and school patterns, controlled in part by bank lending policies prevalent until the 90's. It could be argued that television should have blured the distinction by offering a widely available standard reference for the language. Not so, look at their programmatic content. These are shows with black people in them, therefore black people watch them. The language used in these shows is distinctly different from that written for and watched by general audiences.
Television serves only to further the isolation.
Before television was available to blacks, Ebonics was especially useful around children when adults wanted to leave them out of their conversations. The children had not yet assimilated all of the nuances of Ebonics influenced by black story telling. With it's only anchor being in the Southern dialect of English, it is associated with the plantation and picking cotton rather than schools of higher learning and invention. It serves to hold one back if it is the only English one knows. Unless, of course, one only aspires to work on a plantation.