Nah, you misunderstand Decatur, which is actually part of Atlanta. Decatur disagrees with this notion despite being inside the perimeter, and therefore this is merely one of a number of attempts to be "different" and to distinguish itself as the odd child out-- which it's been trying to do pretty much since being the only town in Georgia to vote against secession during the civil war.

There are even more technological oddities in Decatur that make people want to become Amish, for instance pay parking that requires text messaging to use.