But you are arguing that, Flash.
I asked you why you thought it belonged in a museum, and you said that its because it can be placed within the "complete picture" of the culture and history of the Civil War.
So therefore, if you wave it about outside of a museum, then you no longer get that placement within the complete picture.
Instead, you supplant that context (or, remove it from the big picture), therefore erasing the history of it.
If you pulled just the river out of the background of the Mona Lisa, is it still the Mona Lisa?
If they removed just the river from the painting, everybody would still know it was the Mona Lisa.
Waving a flag outside of a museum is not intended to give a complete picture of its history. The person waving the flag may not care about its history, context, or meaning. People who want a complete picture can visit a museum or read a book. Others are free to wave the flag for any reason they choose without any context or history.
I see people wearing articles of clothing with the American flag or portions of that flag on them. That shirt tells me nothing about the history or meaning of that flag, but he is free to wear it and it erases none of the history associated with it---it still exists in history classes, museums, books, during the pledge and national anthem.