Virgin started out as a low cost carrier and came close to going under, only being saved by the demise of Ansett. It then rapidly ramped up to fill the void, changed to a full service airline, and is now looking like Ansett did before the collapse. An unnecessary mix of aircraft types, bloated office structure, unprofitable routes and a series of "why on earth did they do that ? " decisions have all added up.
With the benefit of hindsight, they would probably have been better of had they stuck to the low cost formulae of one aircraft type and strict cost control. Qantas would have let them have 1/3 of the domestic market and everyone would have been happy. Customers would have been able to choose between a premium carrier or an Australian version of Southwest Air, with the appropriate price differential.