Every Cup Tells A Sad Story

The new TV ad for T** H*****'* puzzles me.  Puzzles me in why they chose that (based on a true) story as the basis of their ad.

Here's the story:
Kid plays street hockey and father tells him that he should be spending time on things other than hockey. Kid is forced to come in and stop playing street-hockey.  It's obvious that the kid doesn't like his father telling him not to play hockey.  The father, based on the inflections of his voice, seems lile something of a disciplinarian.  He rules the roost.
Kid grows up, and is nothing like his dad, because he encourages his son's hockey career by going to the rink and watching him play.  Kid gets surprised at the rink to see his father arrive and sit with him.  Father gives son a coffee (double double).
"Why are you here, Dad?" asks the surprised son.
"To see my grandson play." says the father, coldly.
"You never came to watch me play." says the son.  It's obvious that this has caused him some sadness in his life.
"Yes I did" says the father
"What was the name of my team?"
The father doesn't answer (because I believe he doesn't know) but offers a picture as proof that he at least knew that his son played on a team.
The father, still emotionally cold to his son, goes on to cheer on, and show pride in, his grandson.
Through flashbacks, we realise that the father secretly came to the rink to watch his son play, bringing coffee each time, we assume, for himself and a janitor.  Only the son didn't know this.  All these years the son thought his father disrespected the son's decision to continue playing hockey.
All these years, the son must have born resentment to his father for his stubborn attitudes towards his son's desire to play hockey.
In the end, though, the son smiles and thanks his father for coming.  We're led to believe that, from now on, father and son will be closer.
I understand that this is supposed to be touching.
My wife cries when I watch it, and I know of others who've stated the emotional impact of it.  To me, though, I see the father as something of a prick.  Why couldn't he have acknowledged his son's passion for hockey before now?
What kind of sad, pathetic home life did the son have growing up?  Obviously loving the game of hockey, but not receiving any encouragement for it from his father.
Why did the father need to keep it a secret, all these years, from his son that he watched him play?  Stupid pride?
The only sentimental moment of the ad, for me, is when the son decides to forgive his father.  When he says "thanks for coming".  He could have said something like "you old prick!  Do you realise how hurtful it was, everytime I played hockey, to look into the stands and NOT see you?  Do you have any idea how many times my heart was broken a bit more by your absense?  And now you come here, with a dish-water detergent tasting luke-warm coffee and expect me to be glad you're here?"
He could have said that.
Now that would be a great ad.  That would be a cupful of story.