With all due respect, you're mistaking population for culture in this case. Duval is COUNTRY AF. North Florida as a whole is South South Georgia or South Southeast Alabama. It is what it is.
There's a million people in Duval County, so yeah, there's gonna be a Walmart or Publix within 15 minutes of their homes, but the cultural norms there are always gonna be more similar to a little country town like Jennings or Live Oak than SoFla will ever be. Dade's population is 3:1 to Duval's and I'll bet the ratio of people who eat chitlins is 3:1 in favor of Duval over Dade. I've spent many summers of upbringing on the Westside and across the Clay County line in Orange Park, so I'm hella familiar. I've been in summer camps and played sandlot with early and mid 90's version 10, 11 year old Jack Pyburns, he's a country boy, nothing wrong with that. I haven't been up there in about 18 years but again, I'd bet there's more than one country FM station in the JAX market. Kiss FM is hangin' by a thread down here.
I know what a bumpkinville is. My maternal grandma was born in and grew up with Ray Charles in Greenville, Florida. It's less than 750 people there. Some real one stoplight ****. Go outside in Madison County, take a shovel or a spade and scoop up some dirt. You're gonna see red clay, just like in Georgia. Do the same thing in Jville and tell me what you see...