Love them or hate them, the fact is that most of the cryptocurrency activity comes out of Asia, and China is a large part of that.  So when the Chinese government starts to impose or threatens to impose restrictions the danger is that they are cutting off a huge supply line of investors in that area.  If I said I was banning bitcoin in my house, it would not move the markets, because I am not even a rounding error with the market.  However if China says it then it is talking about potentially restricting billions of dollars worth of cryptocurrency