His argument is not the same as mine ofcourse but..
"First, it is important to understand that the skeptic answer can be seen as simply absurd and hypocrite. Most atheists would not accept subjectivist answers in any other area (except perhaps some nihilists), especially things like science. We rightly blame many Christians for holding Creationist positions on faith and subjective appreciation, because their position is not based on reality. But we must put the same blame on the shoulders of the subjectivist position in morality. To argue that morality is not knowledge and that therefore any belief or whim is acceptable, is not any more acceptable than saying that biology is not knowledge and that Creationist is true by default.
One may claim that in the absence of a possible objective morality, we must fall back on subjectivism. But that is unacceptable: in the absence of objective evidence for a proposition, we must remain silent. We must go to the extent that a rational evaluation of the evidence will take us, and no further. To do otherwise is to indulge in fantasy, which can be very good in art but a detriment in philosophy as well as in our daily experience."
I agree with this part and it suffices to favor my argument.