One day banks will accept Bitcoin as medium of exchange and accept deposits from bitcoiners. As soon as the world powers accept it as medium of exchange.
Banks hate Bitcoin. They don't accept it despite global acceptance. Besides, why use a bank when we can deposit it into our controlled wallet? Why give them a complicated job when we can do it personally? We don't need them. We do it on our own. That is one advantage of having this in place, where we have the fullest control and no need to spend money on others to guard our assets.
In fact, that is why banks dislike Bitcoin, as it will affect their income. So we don't expect them to welcome Bitcoin but rather push it away.