Banks generally charge fees for doing anything with money, even just holding on to it. That's because the banks have created a level of trust that transactions pass smoothly and everything is recorded and accounted for correctly. Therefore, they know that Bitcoin and other decentralised cryptocurrencies allow people to trade directly with each other, cutting out the need for a middleman which, in traditional commerce, is a bank.
Banks aren't happy about being made obsolete and with help from governments they are trying to clamp down on cryptocurrencies after initially dismissing them out of hand.
Some governoments ban bitcoin because they are dependent on the banks, Banks support them when they make a big project for their people. Also that type of governments are borrowed by the Banks and in a result they get press by the Banks. Banks are against the bitcoin because in the future the user will prefer the bitcoin instead of the banks due to its very qualities. It may happen that bitcoin disappear the Banks.