"The most interesting factor is the diversity of these suburbs. They are still predominantly German, but then again so is the country. I live in an exurb of Nuremberg in northern Bavaria. It was the city of Dürer and Hans Sachs as well as the infamous Nazi rallies and post-war trials. It still has castles from the Medieval past, but the need for labor to rebuild destroyed cities – and eventually the resulting prosperity – in the post-war years saw new faces and cultures arrive with immigrants from countries like Turkey.
Just like in America, many of these newcomers worked until they retired and decided that they wanted to stay. Some of their children are having trouble but not all of them. The children that move out of their neighborhoods to the suburbs integrate better because their parents tend to be more prosperous and thus resent Germany less. The other reason is the fact they are more exposed to the language. Cem Ozdemir was just elected as leader of the Green Party here and he does not speak the pidgin common among a lot of Turkish immigrants. I moved to the suburbs for much the same reason. My wife and I are both non-native speakers but we know that if our children are going to succeed they will need to speak German well and act like Germans. Ideally they will become hyphenated Germans, as in American-Croat-Germans, which is roughly what they would be."