You have written my mind.,I have been a freelance recruiter for nearly 2 years,and i totally understand what you mean.English Native speakers are very humble and polite when they apply for the positions,I enjoy reading their emails,but those who are from other countries always destroy your day.I have received so many threatens that i can't even remember,most of them call me a racist which i think I am no way near that,they keep telling me that Cameroon ,Congo,Nigeria.etc are English Native Speaking Countries which completely betrays what I have learnt from my education,They also like to use:my mother is an American(British) while my father is a Nigerian(Cameroonian),you read their emails,and they look almost identical,even the grammar and spelling mistakes.
I don't mean that people from non-native English Speaking countries do not deserve a job in China,but they should value themselves before they apply for the jobs,Chinese English teachers can speak as "good"English as those Africans,but what did they do in past?they dumped the new generations' English.