Back on thread (vaguely), twice I've flown PER-MEL and according to my pax log book its a mere 2 hours 50, weight off wheels to weight on, (with Ansett, the day they went bust!) or 3.04 with Jetstar.
So not an altogether stupid way to connect to the East coast if thats what you want to do. Either direct or with a WA stopover. Perhaps not an obvious route, but if the price is right.....
They won't make a bomb on it, but doubtless as has been covered already, it will suit at least some.
After all, Emirates manages to fly 19 hours Dubai to Panama City, and who on earth wants to fly that?