Thankfully my dog couldn't careless, not even when the little dog takes his ball right from his German Shepard mouth.
But I am curious to know what others would do, I feel the command is a good idea because it can stop them from picking up scraps etc when you have guests over.
I also think maybe the owners in the youtube clip didn't correct the dog when it first started. If mine started doing this, it would be a quick no and removing the food straight away.