I do not see why people like this so much, like George said it implies you should stay in the closet.
Mostly because the fact that he's gay is meant to be a "surprise twist". The class photo was purposely made blurry and he had his finger over the guy's face at times, so that the viewer was not supposed to know that he was talking to a male classmate. Then when his father says that it was an all boys school, the viewer would then realize that the young man is gay.
Of course, the video title and the thread title gave it all away beforehand, but nonetheless, it's an awkward situation that almost any gay person could relate to.
The actual commercial should have McDonalds bringing the father and son together and their shared love of Mickey D's (and the years of shared memories) should present a opportunity for the son to come out.
Okay, first of all, I don't think you apprieciate how gut-wrenchingly difficult it is to come out to your parents, much less your father alone by yourself.
Secondly, who would want to come out at a McDonald's? That's kind of strange, if you ask me. It doesn't seem like a very special or quiet place to do that, but oh well.
Thirdly... who's to say that this fictional character didn't come out of the closet after the commercial ended?