Earlier quoted context omitted.
It’s considered incorrect because the combined cultural output of the previous five centuries established an educated baseline as to what is considered proper. It’s not simply an arbitrary designation or a consequence of “privilege” and culture isn’t just an empty variable that is selected randomly. The point about Australian English is irrelevant. Australian English is correct in Australia and incorrect in America,…
This seems like a very strange position to take. For one, I think what you're attacking here is usually called "descriptivism", as opposed to prescriptivism. Relativism is already a term of art in linguistics for something unrelated. For two, it's hard to follow what point you're trying to make. If you think Australian English is correct in Australia, why not similarly say that AAVE is correct in a place where people…
I didn’t say it wasn’t. Certainly dialects are “correct” in their specific regions.
That isn’t the same thing proposed by the original commenter, who insists that it is correct everywhere.
It would quickly become unwieldy if every cultural subgroup wanted their dialect to be given equal standing with the majority’s agreed-upon standard. Communication would become impossible. Political fracturing would probably happen.