He could have said to Vito: “Pop, I was wrong to distance myself from you. But I atoned: I saved your life. And I paid a heavy price: two murders, abandoned my beloved fiancée, lost months out of my life in Sicily, lost my beloved bride to a bomb intended for me. We’re quits. Now you run the family…Oh, not feeling well enough to take the reins? Fredo not equal to the task? Sorry, Pop, that’s not my problem. Besides, you always said you didn’t want this for me—you wanted me to be a pezzanovante. Well, I can’t be Senator Corleone or Governor Corleone if I’m Don Corleone. Bye-bye.”Instead, Michael chose to succeed his father as Don.
Michael actively chose the Mob life each and every time.
Not that I think this quote from III would escape your eye, but doesn't this at least give some sort of credence to the notion that Mike was forced into the life.........?
"I swore I would never be, a man like him – but I loved him. And he was in danger; what could I do? And then later, you were in danger. Our children, were in danger. Look at it."What could he do? I believe him in this scene, I don't think he is disillusioned. While I agree that Mike's competitive nature made it impossible for him to be a 'half-ass' don, I think that Puzo/FFC's intention was to write his character as one who was forced into the life he led.
I also think that Vito was forced into the life by his birth into the pezzonovante system and later by his life as a poverty stricken Italian-immigrant in NYC.