There are more than 200 guys who have used this option probably in order to remember a nice challenging climb. I guess you and most climbers out there have told their friends that they are coming closer to doing the project and that, "it was done with one hang". You do not have to use this option... It is just a personal feature to remember a nice climb.
Most who have used this feaure have used it for onsight climbing. I guess they like me did want to remember a good push but did not care to try it again or maybe did fall again. During the North Face Climbing Festival, you could actually score points even if you did a route with one hang. I mean, it is the freedom of climbing you can do whatever you want, can't you?
routes - "One Hang"