Yeah. Not that I think that being an astronaut makes you a better NASA administrator. Mike Griffin was an engineer and really did everything engineering teaches you should NOT do in project management.
I think the best NASA administrator would be some boring pale bureaucrat. Somebody who does not mess into science or engineering, does not develop such psychological disorders like visions. Somebody who keeps the budget together, tries to keep his workforce together and his strategic suppliers healthy. Also somebody who does not feel any involvement in the projects and does not feel bad if he has to cancel one or has a pet project to bloat.