That's an interesting point.
China has a pool of 1.2 billion people; does it really need foreign brains?
Is there anything special about foreign-educated scientists that cannot be provided by Chinese people themselves?
In any case, the biggest driver of innovation is good old fashioned human ego/greed. If China can convince its people that fabulous wealth lies at the end of the rainbow, innovation will flow.
I'm sort of agree with you in that there are lots talents in China. However, there are more such (foreign) talents in USA. A larger number only gives a better chance. But talents needs to be nurtured to grow. If 1.2 billion were illiterate, the chance of having talents would still be slim (not null).
Talents do not just arise from classrooms, they do more so from practice of their profession, by attempting to apply their knowledge, by coordinating with their colleagues in practice, by managing resources...
The reason that China is still behind in many areas (compared with EU and States) is basically that people don't have much chance to practice/experience, not that they are not smart/hardworking enough.
The very fact that the US lead in technologies will give practitioners a lot chance to practice/experience with first-rate people, first-rate ideas and first-rate equipments.
No question that China is catching up, but this is no one-jump business. It takes time.
the important part is this: as long as the US can print USD and people accept USD, then it will have an endless supply of cheap and highly skilled PhDs making less than garbagemen. Everyone that has a PhD in science/engineering from the US, knows that a PhD means you are making contributions hundreds of times your salary when you have the PhD: in effect, you are doing more for the degree, than the degree is doing for you. The pie in the sky prize, of course, is a stable job as a professor or company boss, but the majority are stuck as postdocs making near minimum wage while the hot jobs are mostly reserved for native born whites.
The real problem is, of course, cutting losses try to prevent people from leaving. A good way to start is to pay grad students more. Attracting PhDs back is more natural: the better China gets, the more they'll naturally come back. No amount of policy incentives can change that.
We must differentiate
EDUCATION from
JOB-TRAINING.
In general, education can elevate over-all qualities of people. It bestows fundamental knowledge of human achievements, provokes thoughts, imaginations and creativity. It therefore allows you to become highly adaptive to changing environment. Job-training is for you to fit in the current job market (which may/may not be fluid) and earn a living.
A typical example of lacking education but well job-trained is an Indian friend that I once met. He was good in performing his daily work, but he didn't know many basic knowledge (such as where China is!).
To be able to code in computer, you don't need to get PhD. High-school graduates who take some training courses will be enough... and they are actually faster in reflex than older people when coding/debugging code. But they will have problem in solving an engineering problem, for they lack the kind of education that brings them broadened knowledge.
PhD is more of an education than of job-training. PhD is not just meant for money.
We all see many rich people who are so ill educated. We also see many not so rich people who are well educated.
Not denying that money is important. Only sufficient on basic living, can people go for education. Thus, in a society, if PhD is cheaper than garbage collectors, why would people invest for PhD? If there is a singular case that a PhD is starved to death, it is more the problem of the PhD. But if a massive amount of PhDs are starved to death, yet those without PhD survive, will anyone go for PhD?