Ir originated with the slaves because it was cheap and easy to take into the field. Fried chicken could be put into their pockets before they left, and chicken was the cheapest source of protein available.
There are a couple places in Atlanta that have chicken and waffles, I think even a lot of the IHOP restaurants are serving it now. There is a corner diner in Decatur that does awesome breakfasts that serves it and it rocks. Never been to gladys' place, but I have a mini heart-attack every time I eat C&W, so it's a seldom treat.
Then again, I also cover mine in gravy, hot sauce, and syrup, so I guess that could have something to do with it.