Of course not. They had passing grades, many probably had good grades, but they obviously weren't educated . What they care about is whether you learned something. An inflated GPA won't get you in - a good education might. Only if you think we're superhuman.
Books are written by people and teachers are people.
If you're paying close attention and are a good observer, you'll find contradictions in what we know and think. We build theories on the basis of facts and then look for more facts to support the theories. Sometimes we don't find the facts where we expected them to be. Sometimes we wind up with two or three theories to explain the same set of facts. They're probably not all right.