The point is that the airline is being inconsistent. They moved him out of the exit row because of safety concerns, namely that he would compromise the safety of others by failing to "perform the exit row duties" because the OP would be more concerned with assisting his family. The same would be true by moving him to the back of the plane - the OP would would be concerned with assisting his family, and in attempting to reach the front of the plane, would compromise the safety of others.