I've never been able to find anybody who can tell me why it's there. That's what a lot of people would like to know. I don't know why Rock City is in business, but maybe location has a lot to do with it. The ability to market a place to modern audiences may be the big thing. I don't know that there is one reason.
Mountains seem to go after the family trade.
If you consider Texas as part of the South, Six Flags Over Texas was the South's first. I think Opryland and Carowinds came at about the same time. There was a long period when people knew Disney was coming but hadn't arrived yet. Six Flags Over Georgia was important just because no one had ever seen a theme park in the South before. Everything in the park was supposed to reflect this, originally.