Tiger Australia has no hope of making a profit in Australia unless it raises prices (which ain't going to happen). The tiger Australia workers are becoming more unionised, and CASA does not allow any dodgy maintenance work compared to what I have witnessed with aircraft in some parts of Asia to save costs. There isn't really anything tiger can do to cut costs legally. It's the same with jetstar Australia and they both have never produced a profit.
I think the only reason virgin bought a huge share in tiger is to make the Australian airline market less competitive and to scare off investors into trying to start up a new low cost airline in Australia that would impact virgin mainline.