Its just simple, hodlers want more people, government, business, etc to adopt Bitcoin because they want the price to go up and make their profit, and to be honest this is what most people wants. And another thing, Bitcoin gives freedom from using your money without the help of banks and other financial institutions but if banks will decide to invest in Bitcoin, there's no problem with it. They cannot control Bitcoin if they will invest huge money on it. What they can do is to make more money by manipulating the market because they can invest huge amount of money on cryptocurrency market if they want to.