For starters Coke is nowhere near as thirst-quenching as carbonated alternatives like quinine water, bitter lemon or Collins mix. The fact that Coke is an icon of Dixie (not my favorite region) doesn't help at all.
To show how fair-minded I am, though, I will acknowledge that America's vilest (and first) mass-produced carbonated soft drink -- Moxie -- originated in my native New England. Launched in 1876 in Massachusetts as "Moxie Nerve Food," it was promoted as a cure for ills ranging from softening of the brain to "loss of manhood." Its unique taste derives from gentian-root flavoring. As I recall I sampled Moxie just once about a half century ago and it had a faint taste of rotten eggs. I have never had an interest in confirming whether this memory is accurate. Moxie still has a small but loyal customer base in New England, but the brand is now owned by Atlanta-based (!) Monarch Beverage Co. <http://en.wikipedia.org/wiki/Moxie>
Carl