His [Walter's] father and older brother, who together had been the bane of his youth, were alcoholics, and his wife, who was fast becoming the bane of his middle age, had alcoholic proclivities. He's always understood his own strict sobriety in terms of opposition to them – first, of wanting to be as unlike his dad and brother as possible, and then later of wanting to be as unfailingly kind to Patty as she, drunk, could be unkind to him. (3.3.16)
Dorothy had been the only grandparent in his life, and she'd impressed him, when he was still very young, by inviting him to handle her crippled hand and see that it was still a person's hand and nothing to be scared of. After that, he'd never objected to the kindnesses his parents had asked him to do for her when she was visiting. She was a person, maybe the only person, to whom he's been one-hundred-percent good. And now suddenly she was dead. (3.2.164)
It wasn't clear that [Gene] would have married Dorothy if he hadn't made her pregnant, but once they were married he set about loving her with all the tenderness he believed his father had denied his mother.
That Dorothy ended up working life a dog for him anyway, and that his own son Walter ended up hating him for this, was just one those twists of family fate. (3.6.5-6)