Mitchell wrote her novel in part as a way of setting the record straight about the scalawags in the South who dominated politics and high society during reconstruction, by showing them in their roles before, during and after the war. It was more an indictment of the Scarlett O'Hara/ Rhett Butler types than a glorification of them.
As a teenager, running projectors in the local movie theatre, I showed GWTW once a year. People referred to the central characters as"Scarlett O'Hoggish" and "Red Butthole". Believe it or not, the two central characters were objects of scorn to many Southerners, not heroic figures.
As for GWTW being History, that is of course nonsense. It's a romantic novel, a real "girl's book" if you ask me. And I love it, and I think the movie is great, the casting was perfect, esp. Oliva De Haviland, as Melanie Wilkes, who makes the character much, much more than the goody-two-shoes she is in the book; and my beloved Leslie Howard, also a Brit. He probably had no problem recognizing the song Dixie, and he died a true hero for his country and our civilization during WWII.
People should stop critizing GWTW for being something it's not, and enjoy it for what it is, or don't. It's just a story that was made into a big sweeping Hollywood movie. Anybody who would look to things like that for history is bound to be disappointed.