Response: So, this statement belies a fundamental, willful misunderstanding of ecosystems and evolution. You don't get to decide what's an appropriate diet; whether the animal can survive in its ecosystem (assuming, of course, that we don't burn it down and build houses there) is the only actual test. Ecosystems are built up of specific niches, wherein each niche can support a species. For example! Many insects lay eggs deep in trees, where they hatch into larvae. There is lots of larvae in trees, and larvae is a very good source of protein, so that creates a niche: an animal can evolve to take advantage of that abundant food source, and thus survive. In North America and Europe, the animal that has figured out how to get those delicious larvae out of the trees is the woodpecker. But in Madagascar, isolated from Africa for millions of years, there are no woodpeckers--but there are still larvae. That food source hasn't gone unexploited! The aye-aye, a bizarre, scary-looking lemur, has evolved to take the place of the woodpecker. It has a long, thin middle finger, which it taps on the trees to listen for the echo of a grub inside, and then uses its sharp, rodent-like teeth to gnaw out the wood to get to the grub. Is the aye-aye a "bad primate" because it acts like a bird? No, of course not; it simply evolved to take advantage of a food source.