It's a peculiar belief that many NES FT's hold: being a native language speaker qualifies a person to teach oral English to second language learners, adults and children.
There are no university faculty members in the Education, Language, or Cognitive Sciences department of any Western university that would support that claim. 'Modeling' a language (a Community Language Learning concept) has some value when it is supported by actual teachers presenting appropriate curricula, but in isolation a NES is no more than entertainment.
Yet the delusion of their competency stubbornly persists among dancing FTs in China. This is due in great part to the marketing departments of private language schools. Apparently the FTs of EF, New Oriental, Wall Street, et al 'drink the coolaid' that's been concocted for Chinese parents.