A company director is supposed to be honest. We all know that the assumption is more often wrong than true. An auditor is supposed to be capable. We know how easy it is to keep the truth away from him. After the dreams, rather than realities of life.
Answer is simple.
A set of human weaknesses. Most people are greedy. They expect unreasonable profits. So they keep aside reason. A greedy man indulges in wishful thinking and does not want to see logic.