I have lived in both Turkey and Germany.

I lived in Turkey first. The Turk's who invited me into their homes were almost always polite. Even the young male Turks I would meet, when interacting with me or anyone else. The only real exception were Turks who objected to America and the wars in the ME, and directed their hostility at me as a representative of the USA. I cannot blame them for it.

Germany has a sizable Turkish minority, composed of Turkish immigrants during the 1960s, and their children and grand children. I suppose they were invited by the Germans to replace dead German labor from WW2.

In any case, the young Turkish men I met in Germany were the opposite. Sullen. Angry. Threatening. Hostile. Not as bad as the trains in Chicago. But clear and open hostility from Turkish young men.

In a way that never would have happened in Istanbul. Their behavior in Wiesbaden would have caused them to be socially ostracized in Turkey.

From my experience, I decided multi culturalism was doomed to fail. Not that there is anything wrong with Turks or Turkish culture. There is something wrong with trying to fit anybody noticeably different en masse into any culture. It is a dumb idea that we have adopted en masse.