Well, while I wasn't directly involved, I have second and third-hand info that's how it went.
Yes, he continued to grow as a fighter because Kevin Rooney stayed around. And there was some continuation. But with Don King in the picture poisoning the well, the inevitable break with Rooney came and he was never the same after that.
When a guy jumps from an airplane without a parachute, he doesn't hit the ground immediately. It takes time. So it was with Mike.
It wasn't the money or the idle time, it was the lack of Cus D'Amato in his life and the addition of Don King. Had Cus lived another 10 years, I don't know one person involved with Mike who doesn't fully agree that this all goes way differently.