True, the earn/burn ratio when flying is bad, especially in premium cabins. I pay 2 times the price for my J ticket, but only get an extra 25%. But I need 200% of Y points for a J redemption.
However, QFF is not really famous for making points through flying. You make your points through credit and rewards cards.

On AA you typically get 1 mile per US$ credit card spent. For QFF, you can get 1.5 points per AU$ spent so effectively 2 points per US$. Then you throw in your Everyday Rewards card and I get 3 points per USD on a lot of my CC spent, but at least 2.
So when earning in the air, I usually use *A (225% in C at M&M), when earning on the ground, I use QFF.

Of course, all of us would like to see the earn/burn ratio to be improved but I don't think this will ever happen. No incentive for QF to do so unless they assume that giving more miles for premium travel would increase demand.