Even if he voluntarily speaks of his ex-daughter in law, It’s totally understandable because I would feel the same way too, expressing his frustration about the absence of his granddaughter’s mom. Yes, she gets all the loves from her paternal side but the presence of a Mom is just as important as a Dad & grandparents. He just want her to know his feelings about her nonexistent in his granddaughter’s life. It’s a pity.