The problem was discussed several times across different courses for us. Essentially this is all based on Friedman's book Capitalism and Freedom, which says:

> There is one and only one social responsibility of business – to use its resources and engage in activities designed to increase its profits

That is the basis for the argument your professor made. However, the passage in its entirety is:

> There is one and only one social responsibility of business – to use its resources and engage in activities designed to increase its profits so long as it stays within the rules of the game, which is to say, engages in open and free competition without deception or fraud.

Which is a pretty major caveat.