I agree with you that foreign teachers are not one of China's most critical needs when it comes to foreign experts.
I have conversations every year with Chinese teachers that tell me foreign English teachers are not needed.

I would have to disagree. It depends on where you go. If you are in a less developed city or town. The need isn't necessarily seen by the locals as a must. However, if you're in a larger city where people are more exposed to Westernization and Foreigners. People by far see a greater need for an English teacher. So schools tend to push harder in biggeer cities for foreign teachers. Because of the demand is there.

It just depends on where you go. China is a big country. It's not easy to Generalize.