We have the weirdest dogs. The first dogs I've ever met who won't eat popcorn.
Our GSD will only eat meat, eggs, and dairy. He won't touch anything else. He has a lipase deficiency so I only give him very low fat treats. (I mix lipase into his dog food, too much trouble to add it to treats.)
Our lab mix will also eat breads and crackers but she won't touch popcorn.
That's supposed to be one of the benefits of dogs-- they clean up popcorn off the floor!