What happened on Sept. 11, 2001, was not about Islam any more than it was Christianity, or Judaism, or Mormonism. What happened on 9/11 was about terrorism. All Muslims are not terrorists any more than all Christians are terrorists.
As a matter of fact, the wide and vast majority of Muslims are not terrorists, just like the vast majority of Christians and Jews and Hindus are not terrorists. Islam is not a terrorist religion. Christianity is not a terrorist religion. Judaism is not a terrorist religion; Catholicism is not a terrorist religion.