Personally I think that is too simplistic a position and the reality is more complex. Most people would agree that using this approach to spy on your employees to track their banking activity is unethical. Using MITM-SSL as a way to get visibility on certain APTs using products such as FireEye is controversial, but I don't personally believe to be unethical.

I would argue against such an approach if there are alternatives but if the organization's leaders were set on it I would engage with the process and make sure that it did not evolve into more unethical practices such as logging all traffic contents or the above banking example.