Whatever the opinions how political or commercial or blatantly ritualistic the Olympics have become, whatever the political alignment people want to affiliate themselves to voice their protest, whatever one feels about China's lacking progressiveness or equality or environmental policies - stay the fuck away from involving the athletes, in whatever shape, form, motivation, or action. It should not be their concern that China was chosen by the IOC. That's not what sport should be about. Full stop.
Imagine, if the PS politicking of these Olympics prompted the withdrawal of France from the games. (And their rhetoric goes in this direction...)
Now, put yourself in the shoes of athletes.
I know two members of the 1980 US Olympic team for cycling, one a very good friend. He's still not over it. "C'est un scandale !"