In other ways they are a consequence of accepting millions of migrants into the country who have in most cases radically different social, religious and life views to those of traditional French heritage.
But of course, as you say, it is a product of France's colonial past, just as it is in England. And particularly a large part of the problem is the war hero de Gaulle and his "solution" to the Algerian war.
But you don't solve one problem by creating another one down the track a bit.