Ocean Person
Really, encirclement. That's why the airspace is like the way it is? It is the way it is because of the late development of China's economy. The military owned the airspace because there was no civil traffic. They owned it by default. Using your logic they better start making all the shipping go down narrow lanes and let the navy use the rest of it. They don't do that because China has for a very long time recognised the value of trade by sea. At some point someone with some power in the giant machine that is the Chinese government will realise that the airspace will need to be fixed. But it will be a slow and cumbersome process, so don't hold your breath.