I think you've got this backwards. For starters, Jimmy Buffett isn't mentioned in the article at all, and I doubt he's sinking any money into the show. He's super smart about what he does with his money. He was aware that getting the show onto Broadway, even though it probably wouldn't be successful, would mean money later on. Lose money on Broadway, but make it up on the regional tours because it was on Broadway.
He's very savvy. He knew Margaritaville wouldn't land on Broadway. He's in for the long haul, the tours and the hotel. After that, his parrotheads can retire to one of his Margaritaville retirement communities.
The show was just an advertisment to the hotel and retirement homes.