The problem with this line of thinking is it presumes there are only five or six people in the world capable of running a bank successfully and we must pander to them as demigods. If current CEOs are truly "giving up" billions in potential profits then they can feel free to leave their much less risky comp to pursue their billions; don't let the door hit their ass on the way out. There are hundreds if not thousands of equally knowledgeable, connected people, many far better leaders, who would be happy to do the job at a fraction of the comp.
Can you comp the head of BofA $1M a year? Obviously not. Do you get a better leader by paying them $25M than say, $7M? Or if you raise it to $100M do you magically end up with a 4x better person? I'm curious to see the data supporting that assertion? Flag officers in the military make less than $250k a year and I can tell you from first hand experience that they too have the leadership, connections, and knowledge to be making far more if they leave. By your logic, we need to be paying our top generals and admirals $25M a year as well?