Most importantly, linguistics is a descriptive (not prescriptive) science, and its practitioners inform us that BVE Black Vernacular English is definitely a (some say several) distinct and regular dialect of American English. It has been influenced by SWE (Standard Written English) but it's only for cultural and historic reasons that SWE is labelled superior to BVE.

The point being: suppose BVE were (as often labelled) an example of laziness or ignorance or whatever other incorrect derogatory labels your aunt, or English teacher, or the guidance counselor who tracked you for vocational instead of college prep care to apply. Then why would millions of people all come to speak it roughly the same way? Why would the rules of this dialect be just as easily described by linguists as any other dialect? How could it be a useful means of communication? It couldn't...because it isn't lazy, nor's just different.

Why can't we (and our educational institutions) accept and publicly admit, including to students, that there are two dialects? Criticizing kids for speaking their mother tongue, and telling them it's all wrong, is not a successful way to teach the mainstream IS a very successful way to convince kids that you don't understand them or their subculture, and that what you're trying to teach them is how to act white, which will get them stigmatized by their peers.