It's not actually... I've seen traveling in the 70's. Fact is, it's not a natural move to change directions and speed with your second of two steps, that's all it is. Fast guys plant that foot and go left or right. Fast kids now use it because it's a good deceptive tool in your bag if you can do it and it's not a natural move to defend. Not everyone can do it, que the travel!
The chubby kid was so good at it because all he would do is rotate his arms and torso and he changed direction, not much need for a change of speed because he wasn't moving fast to start with.