That's probably due to the fact that some so-called "schools" expect foreign teachers to act like white monkeys in a muppet show; somewhere in the West you would not have to mention that.

In the West, students have little say regarding the teachers who teach them. Contrast China, where teachers are graded by their students. The latter are given assessment forms to fill out once their new teachers have taught them for between a fortnight and a month, depending on the actual school itself.
Chinese students require teaching by way of entertainment from FT's, or should I say, entertainment by way of teaching. So, most schools in China prefer foreign teachers who can entertain.
I taught at a public senior high school in Yuncheng of Shanxi province a few years ago for two semesters. There, my teaching assistant told me that the headmaster was very pleased because one of my classes had been in uproar - the more uproar, the better. Foreign teachers are expected to teach in a very different way from most of their Chinese colleagues, who use the 'chalk and talk' routine. But it's not so easy to become a white monkey if you've been an educator in the West!