because if you bring in an influx of color and foreign diversity, you get people who have less in common, less shared values and don't look out for each other. Get a massive influx of brown muslims in your white country, then find out that you no longer cooperate with each other like you did before. It's basically the way in the U.S. that the two party system also uses race and immigration to drive another wedge between citizens. Believe me, you want homogenity. It's better for progress than diversity. Everyone tells the story that diversity somehow is strength. Nope, never has been, it's a story that just feels good but isn't true. The U.S. progresses in spite of diversity and conflict, not because of it.