They also make the mistake of believing that because people have learned, while growing up, how to behave appropriately in typical business or social situations that those people know what is ethical to do in more complex business or social situations.
Ethics is not the study of what is legal or socially accepted or tolerated; it is the study of what is right and wrong -- in the sense of trying to discover reasonable general principles that will help us decide what we ought to do and what we ought not to do in all cases.
Instead, what we need, I believe, is a principle-based ethics in which, if possible, we figure out what makes acts be right or wrong or what makes things be good or bad, and then have general principles that we can use as guidelines in all situations, along with some thinking and some judgment, to determine what would be right to do.
Principles also can be overridden or modified if there is good reason to do that.
It was a reaction to the harmful hypocrisy they had witnessed in business and in politics and government.