It’s just steering!! (not)
In my opinion, knowing how to properly steer a vehicle is one of the most important things for new drivers (and all drivers) to grasp. Shuffle steering is just one way to steer, but it’s a pretty good method. Your arms never cross, so you never get your arms tangled up in a knot (which happens to people when they’re learning sometimes). Other reasons why I like it are that if the road curves more than originally anticipated, the driver can simply keep shuffling the wheel no problem. Also, it just seems easier and less work than hand-over-hand!
See this post also: How To Hold (and NOT hold) The Steering Wheel