You are assuming that they are honest Muslims. They’re not. There are Muslim invaders in Europe now claiming to convert to Christianity so that they won’t be declined refugee status.
As a side note (and with the risk of tread hijacking)... this is also the basis for the Spanish Inquisition about which Catholics take so much heat. Spain had been retaken from the Moors (muslims) and reestablished its Catholic monarchy. Because the muslims were playing the same game as above, it took the inquisition to root them out.