So? They can just choose to do business elsewhere. China should completely open up their markets, because they seem to prescribe that to everyone else except themselves. We should follow them in kind.
No they can't. If you're a global company like an airline, you can't just choose to make more profits somewhere else instead of making them in China. Giving up a big chunk of international markets can be the difference between being able to compete with rivals, and not being able to and hence and going bust. Really.