Is this, perhaps, because the government does not think this is true?
Or because they do not think it matters?
Or because it is not in the interests of the people they represent to stop it?
I would recommend that you take a good look at Kosovo. Ask the Serbs if it made any difference that the Muslims multiplied like rabbits in Kosovo to the point where they effectively took it over. Empires often fall from within, not from without.
In Kosovo, the Muslims were Muslims.
In France, most of the people whose parents were Muslims in North Africa are not Muslims. They are secular. They do not practice their religion. They are the same as the Catholics who are baptised in a church, married in a church, and buried in a church, and never see the inside of one again.