She loved him and spent all her best years being good to him. He dismissed it. They loved her, and she stayed with them just to make him care.
He still doesn't love her.
He said, "Even if you give me everything you have, including your life, I can't give up a shred of mine for you, because everything I have is obtained by that person's blood and tears." So she finally looked away, she let go, and looked for her own happiness.