I doubt he’s being blackmailed. He’s just making money hand over fist on it and doesn’t want to see the golden goose destroyed.
At some point, when is enough ‘enough’?
He’s so old not that he couldn’t enjoy his ill-gotten gains if he were to retire today at 5pm.
It cannot be solely for the greed of filthy lucre.
There must be a moral facet to the reasoning that would prove to be so damaging and image destroying that they all are too scared to allow anybody to uncover it even after they are gone to their final reward......................