I'm trying to look at it a bit more generally:
You've got this flag that has inspired tremendous regional pride. But many people outside the region view it as being a symbol of something offensive. The flag is later co-opted by bad people and groups to become a symbol of more oppressive and offensive things, offensive even to the people who supported the flag's original meaning. Later on, people outside the region of this flag see it as being a symbol of these newer oppressive and offensive beliefs. The people inside the region may even believe that the flag has been used for immoral and offensive purposes in the past, but still want to reclaim it for other unrelated meanings. However, efforts to reclaim the flag are seen, outside the region and sometimes inside the region, as condoning these oppressive and offensive beliefs.
Now, in my opinion, that's true for both the confederate flag, and the American flag.
Is it impossible to extricate the confederate flag from its meaning of racism? Is it impossible to extricate the American flag from its meaning of imperialism?