What is the author's purpose in writing lucky charm linder, colin

In "Lucky Charm" the author tells the story of a father son relationship that on the surface seems poor. A father taking his son to a gambling parlor isn't exactly what society sees as a good thing for a father to do. However, this is the only time the boy sees his father's pride in him. He sees that he is not invisible to his father and that his father does love him. The father gives up his Saturday poker games in order to attend his son's football games. It isn't until his last Saturday they revisit the poker table. The purpose of this story is to show that even though the father may not be a great role model or provider for the family doesn't mean that he doesn't love or have pride in his son.

Use who. if it wasn't a question, you could put the he in the blank.  if you can put he or she in the blank, it's who.if you can put him or her in the blank, it's whom.