(Assuming you aren't misremembering): That honestly sounds like a really shitty professor.

Ethics are 100% a thing and more people need to improve their intelligence in that regard. What you CAN argue is that morality has no place in business (or engineering (or whatever)). But ethics are not morality or the law.

At this point, I think everyone and their mother is aware of the concept of The Trolley Problem. And... that is pertinent for a reason. Are you going to send the metaphorical train careening into marginalized groups, your workers, your board, or even your family? Or, the inverse of that: Are you going to do something that means you can buy your kids really awesome xmas presents, your board new cars, your workers the nice ramen, or even a moment of lessened horror for trans forlk?

And that ignores the various types of ethics. Even under utilitarianism, there are arguments that you are making a better net good for your board... if only because said marginalized groups suffer so much they will barely notice any relenting.

Improved understanding of what ethics actually are helps to understand WHY good (or more likely) bad things are happening. And it helps those who are in a position to make those decisions to make an intelligent and rational, if not necessarily good, decision.

Back in uni, all the engineering majors were required to take Ethics in Engineering. And it was very obvious who were the libertarian tech bros of the future during that course. But it also, honestly, is the most important course I took in undergrad and the one that has the most use.

And, as a result, when I do recruiting trips/lectures, I tend to cover that topic. I have a nice slide deck of some of the latest horrifying late stage capitalism shit to come out of tech companies as well as whistle blowing stories and I go through it with the students to try to make them think about why they are learning while also finding the people who would be fun to work with or mentor more directly.