Modernism was the very poorly coined term for what was the drift within the world of Scripture scholars. It started primarily within the northern European countries within Protestant scholars, in starting to analyze scripture using historical critical methods; Spinoza had a hand in the matter when he said “The rule for [biblical] interpretation should be nothing but the natural light of reason which is common to all–not any supernatural light nor any external authority”. this relatively quickly degenerated into treating Scripture as just another artifact, removed from Revelation, God, or faith, and lead to an atheistic approach.
The term has been co-opted to mean anything which someone does not like about the Church (thus its use to disparage, for example, Vatican 20 when it had nothing to do with Vatican 2 - or anything else within faith that some people don’t like.
Thus it has nothing to do with Muslims as far as any reports I have seen. what has had an impact is the residual of the French Revolution, which has raised secularism to the “new” religion - again, moving away from scripture believed to be inspired by God, to a much more world-focused, and often morality rejecting approach to life. An enclosed society has a tendency to keep its members “in line”, as both Muslims and Christians have experienced for eons. As members move out of extended families, then out of nuclear families and away from constant contact with same-faith believers, it is easier to stray as no one is there to call one to an accounting.
