I't's certainly true, Strike, that Billy Beane didn't write Moneyball (or appear onscreen in the movie), but he had to put in one heckuva lot of time in the process, let alone providing the author personal access and access to other key folks in the organization.
I may be wrong, but that suggests to me that Billy enjoyed having a different kind of project than MLB.
Of course, I suspect it's been less than fun much of the time over the years for Billy, having to deal with a really small budget, in a small market, and having his plan for a new ballpark (and more money) dashed time and time again (whereas the team just across the Bay has a great new ballpark and much success in recent years).