Trevor,
Easy -the government turned the money tap off and they had to generate the revenue themselves - thus user pays.
Personally i think all this user pays stuff has knobs on it - we fund vital infrastructure such as road and rail so why should the airline/aviation industry be unfunded?
there is no credit for the benefit to the economy and it must pay for itself yet when it goes away (such as during the dispute or the ansett collapse) the economy suffers..
seems to be a bit of a both way bet to me