I'm just gonna link to David Foster Wallace's essay/review of the book "A Dictionary Of Modern American Usage". It touches upon the ethics of dictating proper usage vs how lower class people use language. I'll link two versions, so which ever you find more readable:
https://jenniferlobasz.typepad.com/f...esent-2001.pdf
https://harpers.org/wp-content/uploa...04-0070913.pdf
It's a good read, but long. I read it myself 1-2 years ago in one of the collections I've got of his writings.