The wiseguy answer, of course, is: Because they can. But why? Guo Hui can talk openly about his desire to quit the country because the sons and daughters of princelings are routinely securing green cards and permanent residences and citizenships in English-speaking countries, which fact the Chinese public is well aware of? Jimmy Wu and Gordon Xiao can talk openly about government corruption because the political leadership is talking about the corrosive effects of endemic corruption, which fact—the talk and the corruption—the Chinese public is well aware of?
Your guess is as good as mine. But the fact that the educated private sector upper middle class can talk openly about these matters and how they affect their hopes and fears about their future says that the markers are shifting in mainland China.