'The Impossible’ is Based on a Real-life Spanish Family, But the Characters Are British -- Why?

Spanish director Juan Antonio Bayona, who’s best known for his acclaimed horror film The Orphanage, teamed up with writers Sergio G. Sánchez and María Belón for his new disaster drama The Impossible.  

Based on a true story about a Spanish family's devastating experience while on vacation in Thailand when the 2004 tsunami hit, Naomi Watts plays the mother María Belón. Funny thing is, she’s supposed to be Spanish but her and her husband, Henry Belón (Ewan McGregor), have English accents.

Turns out, Bayona decided not to specify the nationalities of the main characters in order to create a universal film in which nationalities were irrelevant to the plot. Weird. How do you explain their last names? 

According to Miami Herald crtiic Connie Ogle, the family's nationality in the film is shifted to British to account for the casting of Watts and McGregor as tourists who check into a Thai hotel with their three young sons for a holiday vacation and end up facing an unthinkable disaster. 

Given the lack of Latinos and Spaniards in Hollywood movies this year, we can't understand why a studio would choose to take a true story like this and change the characters' nationalities.

Also, why couldn't Watts have played a Spanish woman? Does this upset you?