It is unknowable how much of what took Paterno in the end was his age, the cancer, the chemotherapy, the withering illnesses that sap the elderly in winter, or the effects of the scandal. He always feared what would happen if he ever quit coaching, and that might be a large part of why he never did. As others have also recalled, it affected him to the core when Bear Bryant died just weeks after retiring as the coach at Alabama. Paterno always said he was convinced the two things were linked.
Paterno didn't retire. He was fired by the board of trustees, a group that now seems intent on justifying its actions to the public as a substitute for actually explaining the process. Whether Paterno should or shouldn't have been removed is not the debate for this sad moment anyway.
He will be remembered as a great football coach, among the best of all time. He will be remembered as a great philanthropist, giving away, along with his wife, huge amounts of money to charitable causes. He will be remembered as the greatest promoter of Penn State, lifting the school with his vision of big-league athletics coexisting with exceptional education. No one brought more attention to the campus and the institution than Paterno, so it is tragically ironic that the last skyrocket of attention did so much harm to the school and the coach himself.
Paterno came from a simpler time, and that might have been his undoing. He preferred the early years when, if a player ran afoul of the law, he would take care of it himself and "run his tail off in practice." He believed in a Norman Rockwell portrait of America that had long since fallen from the wall.