I thought this was interesting…

The problem with some grammar rules from the perspective of modern linguistics is that there is not one absolute grammar in the English language. Most American native English speakers equate standard English with being correct and any non-standard variation of English with being incorrect.

In reality, however, the concept of standard American English is really the privileging of a particular dialect of English that originates from the Ohio River Valley. This is the dialect of English that the anchors of the nightly news speak and that we base our notions of correct and incorrect grammar on. It is important to recognize that no grammar is any more correct or incorrect than any other on a functional level, and our notions of correct and incorrect are culturally constructed.

From: yourdictionary.com