Scarlett (in the book at least) is an interesting example in popular fiction of a character who is clearly intended as an antiheroine: she is a protagonist who, like Becky Sharp, is consciously depicted as not being a nice person. Occasionally she wishes she were a nicer person -- she's not villainous, just self-centred and blind to other people's perspectives -- but generally speaking she is firmly convinced that whatever she does is justified.
Most of what we see in the book is filtered through Scarlett's perceptions, and because we see things from her point of view we tend to end up sympathizing with her plight even when she is behaving badly. But what Scarlett thinks isn't necessarily what the actual author thinks (the character of Melanie being an obvious example of this; Scarlett dismisses her as a potential rival the moment she hears Melanie talking intelligently about literature, but the reader clearly isn't intended to make this mistake!)

I have a feeling that a lot of fans don't actually understand the concept of the unreliable narrator and therefore end up adopting Scarlett's view of herself and the other characters at face value...