I ascribe this appalling and stupid tendency to three irritating and pants-on-head stupid root causes. The first is his exaggerated dread of what his people back in Manitoba will think of him. As we're about to see, John lives in terror of disappointing the people back home and most likely thinks that he'll be persona non grata if his kids aren't in danger of overloading the pleasure centres of their brain. The second is, of course, his being ruined by the neurotic mess he married. She's spent most of her life blaming everything on him so he assumes that every bad mood he encounters must be directed at him.
Those pale in comparison to the stupid, stupid, STUPID logical leap that he needs to make in order to avoid a painful realization. Said brain fart is, of course, thinking "I provide this child with everything she could ever need. Why is she ungrateful and moody?" when confronted with sadness because the boomer idiot in him can't see being upset any other way than throwing a fit because Daddy isn't giving her enough. It is pointless to try to explain to him that not everything is about him because it leads to his having to admit that not only is he not the only person who matters to him, he is too vain and silly and scared to find out who these other people are. He prides himself on thinking that he knows everything and a realization that he hasn't a clue is not something he cares to face.