You are wrong. They aren't multi-cultural countries. After 5 months in Ireland, I haven't seen a Muslim (dressed in hijib, anyway). I've seen may six Africans or people of color. In Portugal, I saw maybe a few dozen people of color in the 9 months I stayed there. I didn't see a single person in a hajib.

Nobody is asking anyone to give up their traditions. That doesn't solve anything. The point is that cultures clash, and nobody is going to give up their culture.