Most countries have realized that increasing demand for electronic money and acceptance of bitcoin in some countries will lead to more countries adopting bitcoin as it is a new development trend. Other reason is that they are anti bitcoin because they cant totally put a tax or any other charges thru it. they are arfaid because if more people can recognized bitcoin , sooner or later all people will now use it and the fiat will be totally forgotten . which means they cannot earn an incentives and more. Bitcoin of course every user will be burdened because the government will definitely limit every transaction that happened from each user.
This is their biggest fear if bitcoin were to remain at its current size governments around the world will not care too much about bitcoin, but they are seeing the potential it could grow to be one of the biggest currencies around the world and they do not like it, since the tight control they have over their populations will disappear and as a result they will lose a lot of power.