Very simple. And, yes, one can make arguments about subjectivity of right and wrong, about everyone having an opinion, about this, that, the other. But, the premise is simpler that. The premise shows that the respondent is choosing what he answers very particularly. He's choosing what to answer so as to not answer that which would lessen his argumentative stance. This shows quite clearly that this particular person isn't dealing with the subjectivity of right and wrong. Rather, he/she simply wants to win. Why? Because they're watching. "Life is just a show. People laughing as you go. Remember that the last laugh is on you."