I used to speak with a so-called African-American Vernacular English dialect (AAVE). In the all white elementary school I attended in Minnesota, a couple of the kids there would mock me when I mispronounced words like “with”, or drop an “are” from a sentence. I didn’t think much of this, but thankfully the teacher I had did. I’m grateful for the time she took—and her courage—to personally help me with my grammar. I believe knowing how to speak and write in a reasonably articulate way has helped me get farther in life than I would have with AAVE. More teachers should do what she did.
Proper English shouldn’t be conflated with “acting white.” If someone can’t add fractions, we shouldn’t create a separate category of math for them where wrong answers can be right. AAVE is not a legitimate dialect that should be encouraged. It’s just bad English.