Pig Latin is a totally fallacious comparison. Pig Latin is just a rule of word deformation which changes the phonological shape of a word. The language is still English, it still has the same grammar and otherwise the same phonological rules, Pig Latin is simply a device to disguise the shapes of words. Dialects, on the other hand, differ from each other in terms of grammatical rules, phonological rules, lexicon, etc. It's just as absurd to say that I will intentionally mispronounce the word "bush" as "shub" and therefore I speak a totally new language.
And it is even more absurd to say that because some recognize African-American Vernacular as a real dialect instead of "mistakes" in speaking English, that means they are in favor of blacks rejecting standard English. I have repeatedly explained why that is an ill-informed fallacy to assume. No linguist informed about the linguistic status of African-American Vernacular would endorse such a foolish and racist position. Rather, they understand the importance of dismissing certain myths that have been detrimental to the teaching of standard English (such as the idea held by teachers in the past that blacks are incapable of logical thought if they don't speak the standard, or the idea that one cannot be authentically black by speaking standard English, or that nonstandard English is somehow a moral failing), especially ill-informed attitudes that often often make black students resist standard English because they feel it threatens their identity. That is a huge problem, because the language ideology makes many feel like they'd have to give up part of who they are to acquire standard English. And by calling their English as simply "mistakes", it sends the message that they are just plain stupid and since Black English is used to secure Special Education funding, the message is definitely sent that students are "mentally handicapped" because of their dialect, which again creates inferiority complexes, and even more tragically results in a remedial teaching style that does not focus on excellence and gives far inadequate education in English. What I say is get rid of these unnecessary and harmful attitudes and teach the standard in a concerted, personal, and demanding way that demands excellence. As I said before, teach it as one would teach algebra. One needs arithmetic to understand algebra, and one does not eliminate and expunge oneself of arithmetic in order to learn algebra. Arithmetic has its place. But in an algebra class, one does not use arithmetic to solve algebra problems -- it is inappropriate. By teaching the standard in this way, a student would not need to enter the classroom feeling stupid for not speaking standard English and feeling why bother. It should be presented in an exciting way like learning a new subject or language, not in a depresseing "unlearning bad habits" sort of way which unnecessarily makes English seem incredibly harder to learn than it really should be. Stress why standard English should be exciting, by stressing in the curriculum all the advantages one gains by it. But most importantly, standard English must be presented as a black thing. It should not be presented as a threat to one's black identity. Have local community leaders speak about their wonderful jobs and let the students hear them speak in eloquent standard English. By studying the words of Frederick Douglass, Martin Luther King, and other black intellectuals, literary giants, and heroes, the message would be reinforced over and over that the standard is not a white thing, it is something owned by the black community, and it is something they can master without making themselves any less authentic. But it most important that this message be promoted by parents, by instilling from a very young age the necessity and the "blackness" of standard English.