First of all, I've never seen or heard a coach say to turn sideways (unless running a large distance) and take little steps all the way to the ball. The ones I've seen have only said to take little steps and turn your shoulders as you approach the ball so that you can get set up just right to hit your shot (assuming you don't have to hit on the run).
Secondly, this guy says to take big steps to the ball, and yet he himself takes little steps right as he's about to step in and hit his backhand. Take a look at 1:40. He shuffles a bit with reasonably large steps and then takes a couple of very small steps to correct his position before stepping in to hit his backhand.
So, he debunks a myth I've never heard anyone teach, and then he does exactly what all the pros I've seen tell their students to do.