Why? Was China defending the network from harm? Is Bitcoin under attack and China is allowing the attack to get through? Mining is the process of securing the network by expending resources. If the network isn't under attack: losing miners doesn't matter.
In fact everyone was saying that the mining centralization in China was a very very bad thing. So which is it? Do we want Chinese miners or not? It doesn't matter either way to me. This is a worldwide effort and the short-term movements aren't important. I have no reason to believe Bitcoin is worth less than $20k (doubling curve) when we are trading at $34k.