Maybe I've misunderstood.

It seems to me that your original prediction has to refer either to humans as a group, in which case Luke's counterexample is a good one, or humans as individuals, in which case my counterexample is a good one.

It also seems to me that either counterexample can be refined into a useful prediction: Humans in general don't eat petroleum products. I don't eat spicy food. Corvi doesn't eat meat. All of those classes of things can be described more efficiently than making lists of the members of the sets.