I'm not a lover of things french, but in light of terrorism risks in this day and age I totally agree with them. If it upsets peoples beliefs, they can always go back to their own country. This isn't meant to be provocative or racist but froggies gaff, their rules etc
Algeria was considered an integral part of France for over 100 years until the 1960s. Therefore, a lot of the Algerian immigrants were in fact born in 'France.' Of course, many of their descendants were born and raised in France proper; as were many of the descendants of other immigrants.