I tell you what, if I had a daughter that was worth millions and had the potential to make even more, I'd be her pimp daddy/mommy/whatever too! Epecially because I loved her! Who wouldn't?!?! Better for Joe Simpson to be at the reigns of his own daughter's career than someone else who could potentially take her for all she had. It happens all the time when you have people in your camp that don't have your best interests at heart.
As for Nick, he totally benefited from his marriage to Jessica and his relationship with his father-in-law. And you're right. Jessica was not much of a success before the show, but it's not like Nick was doing so great at that time either with his career. My point is that Jessica will be a success no matter what because of her father whether people like her and think she's talented or not. He's helping her build an empire. Nick on the other hand, in my opinion, will not be as big a success. Hopefully for him, he is. But I just don't see it heppening.