The issue isn't being a modern-day Southerner, the issue was the Confederate States of America. The issue with CSA is that it was a country that separated from the USA for the express purpose of maintaining slavery and racial discrimination, and it attacked and declared war on the USA. Southern traits like friendliness and hospitality should be treasured, but the CSA should not. Like it or not, the battle flag was a CSA flag, and the battle flag was chosen by the Sons of the Confederacy to represent the CSA in the era of Jim Crow and lynching.

As for a state flying the flag, it makes no sense to fly the flag of a country that went to war against the USA. It's not un-American, it's anti-American.