Conflict of interest.
And Zach, to answer your question, you have no idea what he did or didn't accept. Giovinco is a player with qualities that will attract a lot of teams, especially in Serie A. FFS just look at Giaccherini.
The timing of his departure suggests that we didn't believe in him, fine, and it's been a while that we didn't. But it doesn't make sense to justify letting him go for free by inventing rubbish excuses. Just admit that Marotta doesn't know how to handle these situations well without losing money.