That's what the French and the a Swedes thought when they had a Muslim population under 10 or 20 percent. Look at any area - any, your choice - where Muslims represent 50 or more or the population and tell me how tolerant they are.
Don't let your values and your tolerance blind you to believe that your values and tolerance are universal or axiomic.
this is a ridiculous and false generalization, disproved by my own experience living in the United States and being friends with Muslim immigrants.