Good point. Judging BBQ is subjective to each individual palate. If I read correctly this was based on the volume of reviews and quantity and quality of said reviews. That is sort of slanting the playing field to bigger towns and venues from the start. I live in Alabama and love BBQ- and am partial to Dreamland's ribs. But I have been in some 'mom and pop' operations all over the southeastern US that were top notch. However there is no way that they are going to generate enough volume of reviews to make any list.
BBQ in Alabama is pretty good and consistent. Like I said, I like Dreamland. Also like Saw's in Birmingham and Big Bob Gibson's in north Alabama. But the best is usually made in someone's backyard with some good friends and some cold drinks.
Next time you are in NA, try Greenbriar's chicken/pulled pork, which I think is better than Big Bob's. They serve killer hush puppies as soon as you are seated and continue to keep the basket full.
Another place is Thomas Pit in Madison for ribs. Different style than Dreamland.
Watch out for the sauce in both those places though, it is vinegar & red pepper based and will light you up. It seems to be unique to NA, I always grab a quart when I'm up that way.