The problem isn't the flag, per se.
Abraham Lincoln said that he thought Blacks were so physically inferior they should never be citizens and said in his first innaugaral address that he wouldn't free the slaves even if it turned out he had the legal right to do so. Yet, in the time since, he has become a profound mythic figure & martyr of support for Civil Rights- the falseness of his myth is completely irrelevent to the power of the man's name today as a symbol.
Likewise, the Confederate Battle Flag was something different (for at least a some people) about a century and a half ago. Since then, like Lincoln, however, it has become something else. Completely and totally something else. And because it is a visual symbol, hitting the eye and mind with an immediacy that needs no words, it also hits us in a way which makes words not just irrelevant, but moot.
We can still argue about many things having to do with the Civil War- Lord knows we've subjected the general subject to so much glossing and white-lies (so to speak) that we probably ought to argue it more than we do for integrity's sake.
But the Confederate Battle Flag is a complete and total lost cause, and anyone who doesn't recognize that is either naiive, a putz, or a bigot pretending innocence. Like it or not, the Stars & Bars symbol has become so deeply associated with racist backwardness it can never be anything else.
'Look' at it this way- how likely is it that we will reject the lies we currently tell about that open and vocal racist, Abraham Lincoln, making him out to be a friend of the slaves.
Yet Lincoln, for us today, is an abstract concept. A subject of intellectual argument, however sacrosanct he may be.
The Stars & Bars, on the other hand, isn't abstract, it's a image that hits our eyes just as fresh today as it ever did. That's the whole POINT of coming up with flags and visual symbols, so that they hit your eye in a way that by-passes discussion.
There is a vast amount of Southern culture which isn't qualified, much less invalidated by either slavery or racism.
There is a lot that is, however, an there's no better symbol and representatives for it than people who keep trying to save the Stars & Bars because they just can't seem to grasp that the visual symbol of that flag is tainted with associations of racism & hate beyond any chance of redemption. It can never, ever again be a symbol for any aspects of southern culture that shouldn't- and thank the gods are- a lost cause.
Displaying it and then trying to pretend it only stands for the good parts of Southern culture, is like flying a swastika and claiming it is really just a Native American spiritual symbol.