The fun is getting everyone up into the tree, not getting there first. Focusing is improved. You have to work the knots in a sequential process or you don't go higher. First one knot is moved then another is moved. Leave out one of the sequences and you are grounded.
Persistence is learned.
You don't get to your intended target without keeping with the program. No need for the instructor to tell the new climber about persistence because it will be apparent. If you stop moving the knots up, you cease to climb. Persistence is learned in an atmosphere of excitement as opposed to a judgmental environment. Reaching a goal is experienced.