The impulse to eat or resource guard is pretty strong, but somehow this dog has learned its place. A skunk has its own way of teaching NO.
The problem with skunks as dog instructors, is not that the spray does not work to push a dog off; it's that the dog is still rewarded when chasing almost anything else.In addition, skunk encounters are quite rare. What that means is that chasing an animal is almost always rewarded, or at least not discouraged, while the strong NO signal sent by a skunk is very rarely applied because 99.99 percent of the time the animal being chased is not a skunk.
If every animal a dog could chase was armored like a skunk or a porcupine, would dogs still chase?
Or to put it another way, how often does a cow rest his head on an electric fence?