Relevant from other comment:

> I don't know whether you've ever experienced a foreign-language class taught by a non-native speaker, but I've taken Academic Writing classes in English at a top Chinese university and the quality was terrible. English literacy is rare in China even though it is a mandatory subject, so the bar to becoming a teacher is quite low. Often, they'll have an excellent breadth of vocabulary, while being unfamiliar with many idiomatic expressions and cultural references that come naturally to a native speaker.