Back in the old days progression into the airlines was harder and the RFDS was a good option for a pilot who had served his bush apprenticeship but missed out on QF/Ansett/TAA. It was a more secure and better paid option then charter or night freight. Due to the poor conditions in GA, it wasn't difficult for the RFDS to offer a better deal. A stable job with an employer who wouldn't go bust was a big attraction for an older pilot with a family and a mortgage.
These days GA is drying up and new pilots are spending far less time up north and out west before moving on to a better job. Even good employers are having difficulty in attracting and retaining the sort of pilots they want, the bad ones who previously got away with paying below the award just get laughed at.
The pool that the RFDS previously looked to recruit from has shrunk, they aren't competing with third level operators for pilots now and need to improve the package.