Islam is, by definition, a religion and political system rolled into one bundle. It absolutely cannot co-exist with other, some would argue better, governments, possibly run by *gasp* non-believers. That's the fundamentalist answer. Then there are the idiots who decide that the slave trade is a good idea (and it was... For them), that throwing their fellow refugees overboard over a simple difference in religious beliefs is mandated, and coming over to a place for the purpose of hurting people who are unafraid of them is righteous. Or that's what "they" want you to think. Most of the fundamentalists are thugs who realized they could carry out their activities and be praised for them by doing it under the guise of their religion. Note the "their".
Free society accepts the people and allows the practice. A free society ask nothing of you other than to be yourself. A free society favors no person or group, well except for those who are willing to participate in the freedom.
Muslims and Islam don't lend to a free society. They are don't accept anything that not in alignment with their law.