A couple of questions Lisa.
1. Aren't you in an MBA course? So aren't most of the students working or wanting to work in the top levels of companies? And they only see one side of an issue?
2. Is your instructor not present in those discussions at all? Not mentioning that maybe people should be looking at more than one side of an issue?
I think that if number 1 is true and the instructor is not pointing out that there is very seldom a straightforward right and wrong answer to those types of questions, then no wonder I believe that corporations are doing more harm than good in this world.
From reading your "Know it all" discussion, I am convinced that many of those students will not even listen to anyone else's opinion other than maybe the instructor's. I therefore think your instructor should be involved and doing his job of helping the students look at problems more objectively and support their opinions with facts rather than beliefs.
I don't remember ever having any classes where people in the class weren't good at the discussion topic but then in my classes we didn't have such specific discussion topics usually. We did have one class on ethics but the questions were geared to take into account the fact that counselors had to follow a specific code of ethics so it was more a matter of interpreting the various principles listed in the code and how it applied to different situations that we were discussing.
I do know that I believe my ethical standards to be very high and I know your's are too. But even so, I also realize that everything is not black and white and that there are no completely right or wrong answers to some ethical questions. I also know that sometimes life would be a lot easier if I did have only one answer for some questions.