That's why they called it a REBOOT.
A reboot doesn't necessarily mean an origins story. The Dark Knight could easily have been the first movie. It's not as if loads of people saw Begins anyway. You don't need to see Begins to see Dark Knight. I think for me at least it took the entire mystery out of Batman by showing a step by step arc of Bruce Wayne's early life. The action and the villains totally got sidelined because of this.
I've always felt that TDK was the true Batman movie Christopher Nolan wanted to make and that BB was the producers/David S Goyer's pet project. There's a big gap in quality between the two movies.