That's true. And I guess half of them wished they could stay. When people abuse the system, it always destroys the dream of some others. No offences to Chinese people either, their high population just makes them more "visible" when it comes to that kind of problem.

As far as I remember in France if you do a 2 years master's degrees, you have a VISA for 1 year to search for a job. One can even search for part-time jobs during his studies. If you succeed, after 2 years more, you can ask for the French citizenship. But, sadly, it collides with the Chinese policy that rejects double nationalities.