I've said it before but will repeat it here, some people want the Chinese 'system' to stagnate because it suits their purpose.

This is absolutely correct. Of course, there are some Chinese 'educators' in this group too.
What you say about student assessment of teachers is pertinent, but can we really trust the Chinese to weed out only the foreign teachers who shouldn't be teaching? I don't think we can. You see, unlike in the west, teachers here have fewer rights and safeguards. You know, I've heard of cases of adequate teachers being fired here because a Chinese employer was able to attract a foreigner who was likely to be a better teacher. I don't know if you are aware that in your homeland there are thousands of incompetent teachers in jobs. I'd trust what British inspectors of teaching say regarding teaching standards not being met. As for their Chinese equivalents, I'd never trust their gradings! As foreigners working in China, we should focus on self-preservation employment-wise. That's far more important than going overboard because of a few drunken foreign teachers.
Yes, the bar has been raised. The reason why, the global economic downturn has caused an increase in joblessness in the west, having had the effect of swelling the numbers of applicants for teaching jobs in China year by year in recent times. The Chinese have always wanted to raise the bar, now they can do so.
Finally, as a fellow lurker on this board, I kinda expected you to reply to Silverboy eventually. No doubt, that will please him.