It's probably wrong to accuse the Chinese. Most I know actually want to stay, but it's very hard for them to. For that reason, many Chinese choose to go to US/Canada despite being much more expensive (ironic right)

The reasons I've seen are that European companies tend to hire local people; student visa don't come with work authorization post-graduation (the 1-year OPT in the U.S. can immensely help when seeking job - for the company, they can essentially bring you in without any extra cost, and when the year is up, either you've proven your value so they can justify a costly work visa, or they can just let you go); cultural barrier is higher in a homogeneous country; etc.