Somewhere recently I either heard or read a U.S. serviceman discussing the French military assigned with our troops in Afghanistan. IIRC, he related how brave they were, and that some of them had to use names other than their own because their familes would be targeted in France by Islamists if their real identities were used.
Fear of Arab fanatics in France goes much deeper than most realize.
They (French Arab fanatics) are much more embedded in French society than illegal aliens are in the USA. France acts in a way most practical, to keep the fanatics calm and not stir them up to rioting.
To think that France could deport their Arab fanatic population is difficult as it is not an easy thing to determine under French justice who is and who is not a fanatic. Only when there are death and destruction in riots can the French authorities determine who should be deported.
It would be easier to deport 20 million illegal aliens from the USA than to deport 8 million 'legal' Arabs from France.
France also relies economically on Arab countries for resources in Africa. So a mass deportation of Arabs from France would have severe repercussions in their economy.
France has a bigger problem with Arabs than Americans have with illegals that come from south of the USA border.