Now, he is a successful businessman, flying his own airplane, with his own life in his hands. Will he have the time to dedicate to staying proficient so he doesn't end up killing himself, friends, and family?
The FAA, insurance industry and Cessna seem to think he (in the abstract) is capable of this. There's no denying that single-pilot owner flown jets have a worse safety record than professional, 2-crew jets. But that's a subjective matter of risk tolerance. It's not as if he's playing Russian roulette.