As for it not being "apparent overnight", Bitcoin just dropped from $450 to $390 overnight.
I have actually been surprised by this. I thought that they would be smart enough to realize that they should buy as many coins as the can while they still can, not sell at a loss because the government doesn't like it. It's not like that government can confiscate the coins or prevent people from cashing out outside the country.
Why surprised? If suddenly no stores/ banks/ govts accept USD are you going to stock up on USD or are you going to dump it?
The current Bitcoin situation is nothing like that. The purpose of Bitcoin was never to have banks and governments accept it, and more and more businesses are accepting it all the time (not in China, but in the rest of the world, which gives it ever increasing value). In China, it will be able to serve as a secure store of value and investment based on its use in the rest of the world. Anyone who thought Bitcoin was a good idea during the bubble and then changed his mind because the Chinese government came out against it, is an idiot.