Why salt, and no ketchup.

The BK fries coating is not even a flavoring, just a non-soggifier. So if the fries are too old and get cold, insead of cold soggy fries that you throw away you get cold tasteless cardboard sticks. Even ketchup cannot save them. Perhaps coated fries are the reason people use mayo? To completely drown all cardboad immitation fry flavor?