Because if he was paid by check he could offer this exact lame defense.
It’s sort of like someone “selling” you compromising photos for an exorbitant price. Sorry, the idiots, both of them, are getting what they deserve. Letterman’s wife probably doesn’t deserve this humiliation, but she knew what she was marrying.
Ditto (is my opinion also). It was blackmail lightly veiled as a “screenplay sale,” but Dave was meant to understand it as a demand for hush money.