One of the most talked about characters coming out of Suicide Squad… and fans of the comic or the Arrow TV series already new this… is Amanda Waller. The character is shocking in her determination and what she is willing to do to get the job done. They up that in the movie, but they don't take the time to give her a motivation. I knew what it was having already known the character, but someone I saw the movie with didn't know her backstory and it turned her off to the character.
But that backstory is there, in this interview with actress Viola Davis, she talks about what makes Waller tick and how that is what made her want to do the role. I think it would have been nice to get at least a hint of that in the film.
Davis also speaks about working with Will Smith, Margo Robbie and director David Ayers.