There are many reason why a person would defraud a company or a company defraud the public. In fact, there are so many reasons that could be mentioned that I will have to be selective. Furthermore, we need to keep in mind that all people are different. In light of this, let me give you a few common reasons.
First, many people and companies seek to defraud simply because they can. If there is a feeling that no one will know and hence they cannot get caught, they might take the easy way and seek to gain profits by defrauding.
Second, we need to realize that greed is a very strong motivator. There is something about the human heart that always seems to want more and more. Hence, for the sake of gain many people defraud.
Third, for companies, there are other types of temptations. Often times a company wants to save face, because there are too many powerful investors. Hence, they fudge things here and there to make them seem better, or at times they down right resort to fraudulent means.