Have you heard of the "No true Scotsman" fallacy? And I'm not sure if you've noted, but there's a lot of justification for genocide in the Bible:
16 But of the cities of these people, which the Lord thy God doth give thee for an inheritance, thou shalt save alive nothing that breatheth:
17 But thou shalt utterly destroy them; namely, the Hittites, and the Amorites, the Canaanites, and the Perizzites, the Hivites, and the Jebusites; as the Lord thy God hath commanded thee:
What's your point? Because it is/was culturally dominant it's true?
You think I'd become Christian in a Muslim society?!