The good/bad of each parent

The father is painted as a pompous, opinionated, miserly academic and some viewers have mistakenly interpreted the character in an overly negative way. The WHOLE of the movie, however, shows that he's the one who wants to keep the family together and bends over backwards to do so despite his wife's infidelities and the torture she has caused him. He's not an abusive monster, at least not in any blatant way; he spends quality time with his boys, teaching them about literature and playing games with them, plus giving them advice. He plainly informs Walt that he forsook amorous hook-ups with flirtatious women impressed by his writing success because he was with his mother.

The mother is genuinely sweet and an emerging success as a writer, but she curiously doesn't grasp the concept of fidelity and foolishly puts her "womanly needs" above all else, including her family. She goes from one man to another without understanding how this "tortures" her husband and is not in the best interest of her boys' welfare, to say the least.

Both contributed to the destruction of the family, but the bulk of the blame falls on the mother's shoulders, despite her sweetness. What good is sweetness when the person is outrageously duplicitous?