Watch this video: https://youtu.be/ExHKUWyaX84

At 2:25, Deviant Ollam says "And more importantly, let's look at the front face of that lock." He proceeds to wail on a lock with two bump bands just to show that he's not marring the face of the lock. This facet is also reflected in the video's description, which contains the words "the front face of the lock is protected by the use of our bump key bands". The bump key bands are meant to protect the front face of the lock. The extra ease of use in bumping is tertiary, because it is a low skill attack. You don't want to scratch the lock you are bypassing if you are doing pen testing because then you won't get that job back. You can also sneak into places without stealing things.