Dribbling the basketball well requires quick hands, but it also requires great ball control. You need to be able to dribble the ball from hand to hand at different speeds, angles, etc. The windshield wiper behind the back dribbling drill is going to really work on developing that ball control. It also allows you to add some difficulty to a traditional one ball dribbling drill.
As a ball handler, you want to always be challenging yourself with the drills that you do. This stationary basketball dribbling drill will allow you to do that, it will allow you to keep challenging yourself even after you have mastered some of the easier one ball drills.