The death of the mother son bond correlates with the first time he recognizes the humanity and vulnerability of his father. All in an instant it occurs to him just how much of a thankless sacrifice his father has made to put food in his mouth and a roof over his head, and he recognizes that his mother was nothing more than a passive spectator along for the ride the entire time...thus the mother son bond dies, he can no longer respect his mother, at least not in any way approaching this new found respect he has for his father.
He has realized that:
A) His father is not an inexhaustible god that goes off to do god things for half the day and comes back home to encroach upon his child like comfort where mommy knows best.
B) His father is mortal, and that his father will eventually die, and that he will eventually become his father.
If the aforementioned lack of cognition surrounding a father's humanity sounds familiar, its because it's the way women view men in so called happy fulfilling traditional relationships...she doesn't acknowledge his humanity because like the pre-adolescent boy who can't conceptualize his fathers humanity, the full grown traditional wife can't fathom her husband's humanity either.
It is up to men to reject traditionalism, as it deprives men and their sons of an understanding of each other that could be forged much earlier in life... Instead, ironically the adolescent male and his father are alien to each other until they become aware of the harshness of their societies disposable view of them. Its time that men demand just as much of the formative years of their son's lives as the supposedly more "nurturing" mother gets.