It wasn’t their lack of fluency, it was their lack of knowledge that they were not fluent. 
Sandman said[quote]Well, duh… that’s 'cause we speak 'merican… [/quote]
So that accounts for the “American Langage Academy” in Madrid back in the eighties. And to think I was so cynical as to believe they were just trying to restrict their work permits to Americans.
It all started to go wrong during my first Chinese class at wen-hua university when they went around the room asking what was your second language. Everyone in the class listed 2 or 3 languages I replied ‘Chinese will be’ 
I met my best friend in Taiwan in our Chinese class… he is British. Also several of the people in my school are British.
Maybe it is just that they are smart enough to not pay such high tuition so they don’t go there.