Actually, given his interactions with Batman, and the pride he has that BATMAN thinks he's doing a good job, I'd say that picking Batman over Superman is a natural. Superman is cool, but he's nice to everyone.
True! Being liked by Superman is no big deal. I mean, he likes Lois of all people, loves her even, and she has hardly ever done anything nice for him.
Batman is scary, and if he's nice to you, you've really arrived you are probably a pretty teenager of the appropriate age.