one thing that might matter is that muhammad is held up as the perfect man and is to be emulated in all his ways and absolutely no criticism, upon pain of death, is brooked
Christians, likewise, are admonished to be as Christlike as they can
and the comparison is glaringly revealing
being excused for his actions due to common mistreatments of the times shouldn't have application
to borrow a phrase, to show a new and more excellent way
Trying to justify the actions of the Prophet Muhammad is like trying to justify the actions of any genocidal megalomaniac, weather it be Ghengis Kahn, Attila the Hun, Julius Caesar, Adolph Hitler, Joe Stalin, or Mao.