My observation is only that there's nothing in it for him, although he might have changed his tune if he knew this particular story would get national attention. He's already disgraced. He lost his job in Congress. He has absolutely nothing to look forward to for the rest of his life.
He really took a plummet from his high cliff of political success to inmate in some crappy jail. If he isn't clinically depressed, it would be a miracle. What's in it for him to get out of jail for a few hours and make a spectacle of himself? He could do these talks AFTER he's released with little fanfare if he wanted to rehabilitate his image.
If he had been sentenced to jail and to give these talks, that would be a completely different matter, but if he wants to fulfill his sentence behind bars 24 hours a day, I'm not going to second guess his decision.