Back to the OP ...
It's a complete culture clash - between France (a secular Western republic that values freedom of speech) and Islamic extremism (groups of hardcore Muslims who are terrorists - the silent Muslim majority are also a problem, some of whom cover for their homicidal brothers).
One issue is that secular France doesn't do joined-up thinking very well - it wants to fight radical Islam but also wants to let in unchecked migrants from MENA countries. France is currently discovering the consequences of pursuing both policies.
TBH, Islamic extremists do joined-up thinking better than France.