If you print couple trillions and then earn couple billions on it, is it a profit or a loss? Think a bit before answering.By the same logic, if you "print" a trillion then why do you have to pay it back?
And to whom is the debt?
Alternatively we can accept that the $ is real, that the debt is real and that the profit is real.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1