I was raised all over the South, traveling with my Military family. I saw some of the mostest 'Suthren' --------- locales in the Nation. Smerna TN, Ardmore OK, Warner Robins GA (the gnat Capitol of America).
As a USAF recruit, I also saw San Antinio, Biloxi, and Altus OK. My experience creds are well earned.
When Dad separated from the USAF, we returned to my birth place, Peoria Il. As a 3rd grader, I had become keenly aware of how the 'Whee Doggy! people' sounded. I didn't want to sound like that, and I very intentionally used TV announcer's pronunciations to model my own diction.
The Peoria area and really all of Central IL, broadly represents lots of Southern Migration roots. Grampa was from KY, Gramma, was from rural Iowa (is that redundant?) , One hears lots of Suthren accents in the river city, , but it signals a different...read 'lower'... economic and social class attitude which has decided to maintain the Clampet Family speak.
If you don't think that poor grammar, bad diction, low vocabulary command and exaggerated 'Suthren' dialect doesn't matter in economic and social stratification, and that it has no impact in one's destiny, I would suggest a reexamination of that assumption.
Disregard for grammar, diction, proper pronunciation and a poor language skills, and the embrace of 'semi closed societal dialects' will likely carry a negative outcome impact, and can limit opportunity for personal outcomes.
Reread George Bernard Shaw's 'Pygmalion' for a clearer metaphorical explanation.
IMHO, Grammar matters. Diction Matters. One ignores that advice at one's own economic risk.
Will we not mention that a convicted felon in FL who voted was jailed for voting fraud.
As a convicted felon, can he legally vote?