You do have the option of not allowing subs, but then you run the risk of not having anything you really need. It's like a no-win situation. But I can relate to kids not wanting some Walmart brands. Especially the waffles. I will eat them, but there is definitely a difference in taste, texture and quality. And the time your order gets filled can indeed impact item availability. Again, a no-win situation.
My DH would just drown them in syrup. They could be made out of cardboard.