It's a stupid vestige from when Delta was a small airline that rarely left the South East. Somehow MSP, DTW, SLC, LAX, SEA, LGA, and JFK can all function without using "dixie," but ATL (based pilots) can't. Add "dixie" to the list of phrases that should be banned such as, "our metal," "fish finder," referring to non pilots as civilians, "scare bus," and "any traffic in the area please advise."