You want progress, risk, experimentation, and revolution? Put bright young people in leadership roles. You want safety, predictability, stability, and status quo? Put the old pros at the top of the organization.
It is interesting to note that none of the commenters have suggested other candidates for the position. Who would you suggest? Personally, I think Gwynne Shotwell would be a an excellent choice. But I doubt Musk would agree with that, since she is the one making SpaceX so successful.