Interesting posting Mike. I think though that I would add a few points to what the speaker has noted.
First,the number of qualified teachers in China is decreasing rapidly due to reasons beyond the obvious. One of those reasons is of course that candidates for the jobs are not being screened carefully enough. Another reason is that truly qualified teachers are getting the word, or have experienced firsthand, the fact that there are so many dishonest employers and/or agents now playing the "English Teachers for Hire" game in China. Actually, things are getting worse all the time and I truly hope that the government will step in and do something about it. Of course corruption is rampant in many aspects of Chinese society right now, so the government really has its hands full in that regard. But I'm hoping that since they recognize the value of English language learning, a watchdog agency of some kind will be established.
One other point,in defense of my fellow teachers, that I wish the speaker would have noted is that Chinese students -especially university students, can be brutally harsh in their appraisal of teachers. For example, if a teacher is rigid or expects a certain degree of attentiveness and motivation from his students, this may result in a negative appraisal that is not entirely fair and perhaps even false in some cases.
However, again, the point is well taken. Personally, as an ESL/EFL teacher in China that is truly concerned about the future of the Chinese students, I would prefer that before coming here more teachers would get a little more experience at home rather than considering overseas employment as a springboard for their careers. At the very least, working with immigrants can increase your cultural sensitivity. And of course it's a great opportunity to hone one's teaching skills, as immigrants are generally very motivated as well as kind and forgiving.