Why Quinn uses his characters in Ishmael

I've seen a lot of other people ask why Quinn would use a gorilla as the teacher in his novel, rather than a human. The reason that I thought the teacher really couldn't be a human is because another human would likely have the same issues recognizing the problem as the other humans, including the narrator, initially. Ishmael, as a gorilla, has an outside perspective of human society, and is not biased by the "story" so deeply ingrained into the culture of the Takers that they do not know it exists. He also has a better observation perspective than the Leavers, because, not being part of the human race, he can observe the lifestyles of both groups on an equal ground. Ishmael has a perspective that humans cannot have, and his ability to communicate with humans allows him to help humans understand their own predicament; however, rather than simply telling the narrator the answers, he leads the narrator through Socratic dialogue, allowing the narrator to discover the answers for himself. This is important because, if the narrator understands how to reach the conclusions being taught to him by Ishmael, he will be able to fully understand them and more easily teach them to others, which, as stated by Ishmael, is crucial for their realizations to actually be fruitful.