1) In this post, you said 中庸,就是按照客观规律办事, but When I read on, 中庸 to you is more like the 客观规律. Maybe to you, 中庸 are both. Then you just equal 中庸 as Panacea, or Holy grail. But for social science, 客观规律 is hard to pin down, and it is ever changing.
2) 原教旨主义 in this post is more like a label than anything. 发动城市起义 in China was 原教旨主义, but
was not in Russia? All the failed approaches were labeled as 原教旨主义.
中庸 to me is more like equilibrium. And only dynamic equilibrium can be stable, just like a pendulum swinging around the equilibrium point,
it can not stop at that point for long, because of the un-avoidable external influences. It looks to me the reason you labeled the failed approaches as 原教旨主义 (which you think is useless) is that static equilibrium is achievable. And the way to achieve it is through 中庸. If what I understand is right, I would disagree with you. Because of the limited ability of human, we are bound to apart away from equilibrium, and we need to try different ways to swing back to the equilibrium. In this sense, equilibrium is just an ideal state,it hardly exists, (just like 中庸, as I would say). Also, the better political system is the one which can swing back to the equilibrium without breaking the system.
In this sense, In my opinion, US still has the better political system.