First, yes, it is SO IMPORTANT
i guess the biggest mistake is talk about a country in general. When we talk about marbella and saint tropez, are very specific destination. In my opinion, the most beautiful girls are there.. as you said, even british girls are super hot.
It makes no sense talk about Venezuela or Colombia as countries, since they have so many people, its almost impossible to "judge"
Even Rio.. people mentioned Rio and i disagree a lot. People go to Rio and visit Ipanema and Leblon. The city of Rio is bigger than the country of Finland. They dont even visit 2% of Rio.
About USA. Maybe it was the most mentioned country, with cities like LA, Vegas, New York and so on..
As i said.. its a country with continental proportions, so it dont even make sense say something like "americans are fat" or whetever..