[T]he religious requirements are so stringent even locals will have a hard time getting work there.
Thank goodness for small favors, but what's the unemployment rate in the area? Some people might be desperate enough for a job that, to quote Winston Zeddemore, "If there's a steady paycheck in it I'll believe anything you say."
Also from the article:
When Ark Encounter was originally approved for much larger tax incentives they were required not to discriminate in hiring.
There's no tax incentive small enough, or potential benefit from jobs for the area big enough, to justify public money being used to support a business that discriminates.