This does have a very real world use.I don't know how much good this skill will ever do anyone, but it looks like fun. And who knows, maybe it will come in handy at some point?
I've thrown knives for fun before and I am all right at it. I understood this guy's technique and I think it would work. He's just using his fingers atop the handle to eliminate the spin. Not saying it's easy to learn, but it makes sense to me.
If you have any daughters just be practicing this on a man sized target aiming for the groin when her date shows up. Then let him know about your rules.