Come on man. Are you really that bitter about the experience you had here. I can't talk about the crappy conditions at Sunny English because I don't know anybody that has worked there, personally, so I can't speak to their problems, that seem to be pretty bad. But to condemn an entire region as you have is not only just outright rude and insensitive, it also shows a lock of overall respect of people.
Firstly, Shenzhen, Shanghai and Beijing are no more "Chinese" than Hong Kong. They are about as western as you can get without being in the west. If you want to talk about a large city that is developed and still authentically Chinese, then don't bring up the tourist commercial traps, but instead talk about a city like Xi'an.
Secondly, I know about 40 foreign teachers here in Hohhot and they like it. It is a growing city. If you want to experience a developed city that is advanced and has all the posh comforts of a first world country, stay in a first world country. You don't come to China to get an American standard of living unless you are dense.
As far as the people of the region go, I have heard repeatedly from many foreigners and experienced myself, that the farther south you go in China, the more rude the people become. I don't know why this is, but it seems to be there.
I have been to Beijing, Hong Kong, Shanghai and found them disgustingly western so please, if you want to experience something interesting, come to Hohhot, where you can get a mixture of Chinese and Mongolian culture. See the grasslands, and enjoy lots of conveniences of major city life without being in a major city. And please, have some class, a little humility and much consideration for people and their culture before summarily dismissing them to the garbage heap of civilization.