I just want to start by saying. It's impossible for Banks to take control of Bitcoin. In order for that to happen, they must Hold, over 50% of the entire circulating supply.
So Unless the banks open up the world best mining farms right now. It's... yeah I'm going to say impossible.

Secondly, the banks already have their Currency of choice.. That would be Ripple.
That's why I can promise you that you're never going to see Ripple at $10