I can see how this could be offensive or distasteful but from a purely academic point of view it's interesting to see that a master-slave relationship was more than a contractual relationship. Leadership was just as important in that relationship as it is in a manager-employee relationship. And although we have since abolished slavery, we will always need leadership skills.
If your mind is open and is able to understand nuance (able to keep similar concepts separate amid complexity) then you can learn from history and take lessons from the masters (bad joke).