Why is she calling him a loser?

Question

In the very last scene of Moneyball (2011), Billy listens to song that his daughter recorded for him while driving in his car.

She changed the lyrics in the end, singing

You're such a loser, dad,
you're such a loser dad,
just enjoy the show.

I don't quite understand what her motivation here is for calling him that. He achieved what he wanted, to change the game. He also did not accept the high priced offer to change teams, so he was staying in town (what she wanted).

So I guess she is meaning it in some sort of ironic way? Can anyone shed some light on her motivation to change the lyrics in this way?

As it is the last thing you hear before the movie goes dark, I guess its supposed to have some meaning I don't get.

Answer 1

Most reviewers are referring to it as something akin to a "loving, teasing tweak." Here's a take from a reviewer at Baseball Nation:

In professional sports, there's no epithet worse than loser ... but of course, in this context -- the context of a loving relationship within a movie that's less about winning than thinking -- it's not an epithet at all. It's a term of endearment, a message of love from a daughter to her father and also from the filmmakers to us ... It doesn't matter if the A's didn't win the World Series. It didn't matter if Billy Beane was, and still is, a "loser" according to the traditional standard. He's a winner because he fought the good fight and because his daughter loves him enough to sing him a song, and tease him.

This review compares the movie to the book, with nods to the movie humanizing Billy Beane in a way the book did not. I have read the screenplay for the movie, and it doesn't end the way the movie does, which is interesting.