Because its a new tech with a new implication. They make their law to protect their currency or anything that may affect them. But i believe once big country already use it, and the application of btc is found in everyday's necessity they will open up and adopt it too. Maybe not all of them but some for sure.
Some governments in Africa are very conservative. In south america too. They don't let people to have their economic freedom by using crypto currencies and they ban it. Simply.