The Beijing Olympics have long since passed, having occurred over 5 years ago and ultimately been an incredible success. There was no real mainstream protest against the Olympics, and there was almost universal consensus that the games were a success (as were London). There are talks of protest every Olympics, but ultimately countries try hard to avoid depriving their athletes of opportunities to shine.
China's response was justified because their security was at risk. We should not boycott Olympics in the first place. All that does is cause more separation. When the Olympics are set in a certain country it does not mean that we have to agree with everything that country does. The Olympics are about coming together as humans.