Here is an example of why marginalization of minorities is bad for the whole of society.The largest minority group in France are immigrants from North Africa, namely Morocco, Algeria, and Tunisia. Coming initially from former colonies as cheap labor, they settled in low income run down housing complex in poor suburbs.While the French society puts pressure on immigrants, accepting nothing less than full assimilation (not mere integration), that society never accepts foreigners who have a different language, different religion, different skin color, and different customs.The result is a no-win situation that leaves many youth feeling alienated. They only have mediocre education if any, have no permanent jobs, and have no hope of keeping up. Many succumb to drugs, crime, or religious radicalism.
Various writings on culture