China is in the list of banning bitcoin. Earlier China closed a major mining pool. This really bit affected bitcoin growth while this happened. But if you look at on the other side, we have other new countries like RUSSIA and JAPAN have adapted bitcoin into their countries. They legally announced and accepted bitcoin.
Bitcoin growth is going to affect the country economy. You can take this in two ways. This would affect current fiats value, or if bitcoin is accepted, the respected country is going to have a massive growth in wealth. Not only the country, but also the citizens as well.
Yes it is actually given already that bitcoin can really affect one's economy, especially in term of money. But we can actually concluded that bitcoin will always bring positive impact to our economy. Sometime it also bring harm , for example some people in the country can exchange their bitcoin , into their local fiat without paying any tax. And it hurts one's economy. That's why they are really carefull in letting the bitcoin be part of their economy.
You have a point, I agree that bitcoin had large effect to the economy of each nation. Other than that my answer to the wider banning of crypto currencies we're depends to each countries because China have lack of power to call wider crypto currency ban. So they have no capacity to control the decisions of many leader of each country.