I think a lot of Europeans find it difficult to understand why people from North America are interested in their roots but I totally get it when you are from a young country - family history is interesting and fascinating and it's ok to identify with places that your ancestors are from. But if you are born in the USA to Italian or Irish great grandparents, you really are American. What Hilaria did is completely different of course - she lied about where she is from which is really weird and odd and I think that lying about who you are points to much deeper issues.
And I think a lot of people here are confusing culture with genetics. It is absolutely inevitable that the culture you grew up in is going to be most influential over who you are as a person regardless of where your parents or grandparents are from. Genetically, I am 15% West African but I have never been to West Africa and I know absolutely nothing about the culture. After I did the DNA test, I became a lot more interested in finding out but I would never call myself African! That's utterly absurd.