Around 1936, how much was known of the monster Hitler would turn out to be? IIRC, the world hadn't even known the nefarious designs they had for the Jews, in that year. Contrast that with China's case.
What exactly are the parallels between the Berlin Olympics and the one in Beijing?
The history of the Olympics was much younger then too. We have the benefit of hindsight now. We can see how Hitler used it as propaganda. And, as you say, we already know about the decades of ongoing atrocities the Chinese have and are committing. No excuses this time.