When someone asks me why Muslims don't denounce terrorism, I suggest that he or she Google the words “fatwa against terrorism” (80,000 hits), or name cities in the Muslim world that held major demonstrations against the 9/11 attacks (Tehran, Karachi). Most Muslims do not approve of terrorism. Their response to it is fear—fear of extremists who seem unconstrained by mainstream Islamic law, fear of a son or daughter becoming a "holy warrior," fear for the future of an entire faith community.
Mullahs in the corner of Pakistan where I live tend to be brilliant orators. They usually speak extemporaneously for an hour before Friday prayers. They can be persuasive, humorous, conciliatory, prayerful or bellicose. Frequently they break into song or weep for the sins of their tribe, and they hold their audiences spellbound, displaying a masterful use of repartee and the timing of a stand-up comic. They can move listeners from tears to laughter in the time it takes you to fold your turban.