As I said in another recent thread:
You might ask, “if it’s a sociolect, then why aren’t other sociolects like, say, ‘geek talk’ also documented and talked about so thoroughly?” The fact is that it’s a very interesting regional, ethnic sociolect. It shares things like grammar rules very similar to African creoles, without actually being a creole, and is spoken by a very large amount of people.
It’s not just a way to separate black people into the “other” (though non-linguists may attempt to wrongly use the term to do so), and it’s not to imply all black people talk like that, or only talk like that, or have difficulty talking in any other way, or anything else unsavory. It’s just that it is a very interesting, very unique subclass of English that has interesting rules that linguists can use to get more complete and better data about how language works. Though, and I admit this openly, people who talk about AAVE and aren’t using it in a linguistic sense (or perhaps a sociological one) are probably using it either mistakenly or maliciously.