I think what was meant when they stated "$50 an hour" was base fare without baggage, card feed, food, legroom, change fees, no shows, oversize fees, and so on.
So your $50 "per hour" plus ancillary charges, the fare doubles once the flight is done.
One quarter of Jetstar's revenue is ancillary. Intra QLD however, greater % is carry on. If everyone checks in a bag = 5k revenue. If they don't, then your margin is squeezed.
You can travel with Ryanair London to Athens for a bit over $40 (2400km) so is $59 lossmaking ?
But how many people fly for $40 with no ancillary charges? It's a few %. Ryanair's average fare is more than 2.5 that, thanks to ancillary.