A Thief is Not a Hero
Vaan, Balthier thinks, will never be much of a sky pirate. He doesn't seem to grasp that no good deed goes unpunished; that a sky pirate is a thief with an airship, not the cavalry - even if they are to blame.
Balthier tried to explain it once; from the look on Vaan's face, the message hadn't got through. Vaan still sees the glamour and the freedom, despite everything else that's happened.
Sometimes, he suspects that Vaan is going to end up a hero masquerading as a sky pirate.
Sometimes, he suspects that that is exactly how Vaan sees him.