Earlier quoted context omitted.
Germany also has a diverse culture, especially because it wasn't a unified state until the end of the 19th century. So the generalization is on both sides.
> Germany also has a diverse culture Compared to what? Compared to Madison Wisconsin, maybe, compared to all of Wisconsin, probably not, compared to Texas or CA, not a chance. Heck, South San Jose is more diverse.
In my personal experience (I grew up and spend most of my time in different parts of Germany and Europe, but have worked and lived in Boulder, CO) there is a very distinct and unifying American identity that you do not find like that in Germany. A lot of Germans in the south will define themselves first and foremost by their regional identity, the same is true for people from Hamburg - and the differences are striking, as most Germans from who are from one region but have lived in another will confirm.
That said, comparing whole nations in this manner is entertaining, yet rarely a really fruitful enterprise. People in Wisconsin probably share more similarities with people in Meckelenburg-Vorpommern than they do with New Yorkers, the latter being more similar to people in Berlin etc etc.