If that were true we would have succeeded in wiping out the Welsh and the Cornish over a century ago.
The South is not a "system" it is a culture.
Compare to the Roman attempts to wipe out Christianity, or the multiple vigorous attempts to wipe out Judaism.
Nazism itself was a relatively short lived political ideaology, so it was relatively easy to wipe out, because you didn't have to attack Germany's underlying culture (which remains largely intact).
Bookmarks