And implying that simply because people speak the same language they have the same culture is nuts. People in Utah have the exact same language and accent as people in California but the two populations have very different attitudes about family, education, marriage, religion, and government.
In fact you don't even need to cross state boundaries. Compare Park City, Utah with St. George, Utah. Different cultures. Compare any metro area with any rural area.
(Just to clarify, I don't mean to imply EU>US, just underlining the difference's depths)
In that sense, the US has a broader base of those enclaves within the country and less time to have built a coherent cultural identity between those populations.
Europe, by contrast, hasn't forced the veneer over all of the enclaves (eg, single language), but the enclaves share a more similar historic background.
It's different kinds of diversity, really. Stable multi-components versus broader partial fusion.
Yup. Consider that in the last world war italians and finns didn't even fight on the same side until a certain point in time.
Europe is a melting pot of cultures and to be quite honest I like it that way.
Why? Because there is a bloody border in between. These are different countries, they have evolved separately for centuries. Don't you get it? Those are not two states of the United States of Europa, those are countries forged with a millennium of historical evolution.
People from the north of Belgium don't speak the same language as people in the south of Belgium. The dialects of German spoken in the north vs. the south of Germany are so different that they struggle to understand each other. If you want an example of people speaking English, compare accents in Scotland or Wales to that of London, which is a melting pot of everything from Cockney to Received Pronunciation. Now, imagine what it is like in between countries.
Seriously, trying to say that the difference between the accents of Louisiana, Socal, New England and Chicago are a big deal, throw in the Mexican accent, hell even a good dollop of Spanish, it is still really homogeneous. Compared to Europe where there are places two hours drive away from you which share none of the languages you speak, and where you will find nobody who speaks any of the dominant languages in the area you currently are. And not just a village, or a suburb or cultural enclave, but whole cities of people.