I think in China they love all the top players equal, so no matter who is on the court (Fed, Rafa, Nole), they will worship him and admire his skills. I think they are like that in all sports.
In US, that is not the case. They pick their idol and stick to him, never cheering for his opponent. Even if his opponent is playing superb.
They love winners like Michael Jordan, Tiger Woods and Roger Federer.