That may be true, but in situations with significant power imbalance it's important for the person in the position of power to recognize it and to not wield it

That may be true, but in situations with significant power imbalance it's important for the person in the position of power to recognize it and to not wield it inappropriately. A joke like that when somebody is under interview stress has the possibility (not the guarantee, but the possibility) of harming the interviewee's chances by nudging them in the wrong way at the wrong time in a tough situation, and that's pretty lousy to do to somebody.