Carpet baggers, the lot!Interesting idea...but one that is specifically wrong AFAIC. If anything, the southern accent (at least the over-done, exaggerated, and corporatized southern accent) is one of the only regional accents to persist. Just listen to country music -- currently one of the most popular commercial music genres. Every country singer - even those born in the north (looking at you, Clint Black and Jo Dee Messina) or even in another country (Keith Urban) -- somehow feel the need to sound like they were born somewhere south of the Mason Dixon line and deep in the boonies.
I actually like some country music...but can't abide the over-the-top southern accents most singers put on.