But why is the food gone?

The Feeders have reverted to their habit of allowing us only the crunchy food they call 'kibble'. It is, we suppose, edible, and they mutter about it having healthful properties. When they are gone, however, the interloping ones provide us with salmon and Felix Milk. We do not wish a permanent absence of the Feeders, but rather the best of both worlds. Why can the Feeders and gooshyfood not exist together?

Why, why, why?