The French are less tolerant of alternatives to their "Endarkenment" humanism. Since the Reformation, evangelical Christianity has NEVER been generally welcome there. Even the Jansenists were intolerable to them.
Pluralism 1]The condition of being multiple or plural.
2]A condition in which numerous distinct ethnic, religious, or cultural groups are present and tolerated within a society. 3]The belief that such a condition is desirable or socially beneficial. 4]Ecclesiastical. The holding by one person of two or more positions or offices, especially two or more ecclesiastical benefices, at the same time. 5]Philosophy. The doctrine that reality is composed of many ultimate substances. The belief that no single explanatory system or view of reality can account for all the phenomena of life.
Perhaps this is because the British are more pluralistic & have repudiated more of their Christian past than the French (who after the Huguenots, never had much anyway), hence the vacuum filled by Islamic radicalism.
I'd rather lose the fish & chips than the legacy of constitutional representative gov't.