He built a small empire on genocide, polygamy, and pedophilia, and that showed his successors what was possible from pretending to follow the tenets of that phony religion. Islam is profoundly opposed to capital formation (no banking, no charging interest), to free markets (everything is controlled by the despot and his kin), to all personal liberty, while requiring the most abominable acts from its practitioners. The reason there are no moderate Muzzies is that there is only one Islam; it’s not the doctrinal differences that make them different, it’s the common behavior that makes them all the same.
I’ve never read it, but I’ve heard it said the way the Koran is written it is not open to varying interpretations nor can that religion be reformed, as has been a constant process in the development of Christianity.