Mike on the one hand lost one of the most important teaching of Vito, to be reasonable. Everything he did in GF II, was not too reasonable. All his enemies were serverly punished or debilitated, Roth was taken into custody, had a major stint in the hospital and the end was near. Fredo, ousted from the family, at least the inside and Pentangeli was a prisoner, all got their punishment, but he still saw it fit to have then squashed and to what end? They all lost, lost something so humungous. The only one who really deserved it in certain terms is Roth, but Mike even lost Rocco in doing so.
The bottomline is Vito spoke from the head and the heart. He was very compassionate and Mike wasn't, although Mike was very brilliant, no doubt, he was never truly compassionate. I think MP was a little ahead of his time with this commentary. Even the Dali Lama said that we spend so much time developing our minds (in the west) we neglect our hearts.