In the same way that you can't generalize 'US Of A' on anything either. East Coast vs West Coast vs Middle America can vary wildly on different topics.
True, but the USA, unlike Europe, is considered a single nation-state. In European countries there are differences within national borders as well, e.g. northern part of Italy vs Sicily. That said there are definitely great commonalities in Europe that can be generalized, my point was that this metric isn't one of them.
And I am actually surprised with the quoted 1/3rd figure for the USA. Might be true but not what I'd expect from my outsiders insight into American culture.
Yea, but a lot of these figures are based on statistics, and sometimes it doesn't take things like the varied socio-economic situations around the USA. I would take figures like this to be more accurate the more localized that they were (i.e. '1/3rd on the West Coast' or '1/3rd in major cities' etc)