If we counted the number of people the PRC has killed by finding them through their "great" firewall, does the OP think that number is less than bad baidu medical ads? I don't understand is the false equivalency between baidu's advertising and PRC's notorious human rights violations. This post doesn't address any of the concerns brought up by the original letter they decry?
Your argument would make sense if ending DragonFly would end the Great Firewall too.
Just because you can't stop something, doesn't mean you should actively support it.