But in China you cannot be totally secure in your job if you're not teaching well. Average teachers are fired frequently a month or two into their contracts, leaving them out of pocket as a result of having bougnt a single air ticket to get there. So, western grovelling weasels abound in China, even old ones!

I agree. The problem the way I see it is that the playing field is not level. I've seen bad teachers not being shown the door during their contracts at some schools. But at other schools I've seen adequate teachers dismissed prematurely due to derogatory assessments re their teaching from students, at least that was what was stated. But sometimes that can be a fabrication by the Chinese head of the English department to get shot of a foreigner he (or she) doesn't like. Older foreign teachers are often wary of being fired prematurely by schools seeking young foreigners who can entertain students better.
Just to get back to this Filipina thing. I'm sick of reading posts by Filipinas bragging about their teaching qualifications and experience. In fact, don't they know that there are Chinese teachers of English who can do the same, though not many? And though nstive speakers of English have the edge re pronunciation and speaking better English, there is a far better choice for schools than either of those two groups.
The best teachers of English in China would be the now grown-up children of Chinese expats in Western countries whose mother tongue is English, but who can speak standard Chinese well. Incredibly, dumb school directors dislike employing them because they look facially of Asian origin! How stupid and unfair this is! The Chinese education system is in a mess, so it doesn't deserve the best teachers. I'll leave it at that.