The Islamic cultures once were important centers of philosophy, science, mathematics, and literature. Just go through a technical dictionary looking for words that start with al- (Arabic for "the"): algebra, algorithm, alcohol, aldehyde... We have them to thank for the Alhambra, Leyli and Majnun (whose influence stretches through Tristan and Isolde, Romeo and Juliet, and Derek and the Dominoes), and the poetry of Rumi. (Speaking of the Alhambra--the Moors were considerably more tolerant than Los Reyes Católicos, who offered the Jews the choice of conversion or eviction shortly after coming to power.)
So, how on earth could such a culture produce the vile beasts who now rule Iraq, or who make sure schoolgirls dressed "indecently" don't escape burning buildings? Are such people the norm, or are they as reviled in their culture as Nazis and their deluded followers are in the West? I'd like to think the latter.