I think the main issue here is that cryptocurrency challenges the debt-based monetary policy we are all used to. That fact that banks don't "print" bitcoin is worrisome for them since they can't charge for introducing currency into the market like the Federal Reserve does. Cryptocurrency will continue to become more popular. At the end of the day, value comes from goods and services and currency is just a medium of exchange people can agree on. The banks are worried about losing money, but governments don't mind as long as you can still be taxed.