Why does the daughter end up singing about his dad being a loser in Point Break?

That wasn't the original lyric, which ended with just enjoy the show.

I think it has something to do with the plot. Most of the show is about Pete (the little girl's dad, replaced by actor Brad Pitt) breaking the mold and going out of his way to dig up players in a unique way that ends up being a success, but that kind of thing only happens to a very small number of people, after all. More often than not, due to the imperfect scouting system at the time, many young people were hit on, thinking that there will be a bright future and give up their original dream to become a failed baseball player, and really into the profession only to realize that they are not at all suitable has been unable to turn back. In terms of team management, his deviation from the norm, defying all odds and sticking to his own ideas to achieve success contrasts sharply with Pete's earlier lack of commitment to his own ideals. Even though, he has accomplished something now, the dreams he gave up when he was young are priceless and simply cannot be compared to that. I think that's what the little girl meant when she called his dad a loser.