It's not about making an evil person not-evil. You don't have to be evil to make evil things. The point of ethics classes is to learn how to think ethically. How did old and modern philosophers think about ethics? If you're an evil person, then law enforcement should be there to discourage you not to be evil and hopefully penalties are high enough to stop you. But if you're not an evil person, and the law gives you certain freedom on ethically sensitive issues, then an ethics class will help you how to reason in such situations. When I don't debug my code properly sometimes I feel terrible because a bug can significantly change a person's day or maybe even injure them (I work in telematic industry). Being a competent engineer requires one to understand the implications of one's job and act accordingly which may be debugging properly etc...