For game theory, bitcoin will evolve to be Bitcoin. Pro Bitcoin and Pro Banks for Bitcoin is the best result obviously. If Pro Bitcoin keeps going on and Banks are anti-bitcoin, then bitcoin will suffer in the short run and banks will continue to profit. However, as you say if banks don't get in , then they will be made obsolete my bitcoin in the future. It's banks to figure out if they want to stay around or not, and cryptocurrency is the only way.