The kind of employers I've been working for in China are generally those who have had negative reports posted about them online, just like the lousy scenario you've described in your make-believe situ.
Obviously, msny motivated FT's will avoid that kind of employer, leaving only the bottom of the barrel or those who are unqualified age-wise or certificate-wise to apply for teaching jobs there. and they're the ones who will get those jobs, and then most of them will make sure they do the minimum there. Not all teachers need to be motivated. Hell, teaching is just like other jobs, teachers vary from incompetent to competent, lazy to diligent. That's nothing new! Maybe the lack of response to your nightmare scenario means few readers give a damn about it!
Personally, I'm only in this game for a job with lots of free time for me, and a more than fair salary for what little I do. And I prefer lsid-back backwaters. I hope that satisfies your curiosity.