Maybe you should actually spend some time in China before making silly assumptions.
The Chinese government is not overly concerned with individual citizens sharing anti-government sentiment. It's not a problem for most people that aren't activists. Most people are concerned with much more basic aspects of life... supporting their families, getting good jobs, time for leisure...
It doesn't mean it's acceptable, but assuming that every Chinese citizen lives in fear of the government cracking down on their political complaints is totally unfounded. The exchange student you know could just as well have been sick of westerners thinking they know more about the CCP than someone raised in China.