Who cares if Jetstar pilots are fatigued?
Anybody that has an interest in the safe conduct of airline operations.
Airlines are not simply vehicles for the paycheques and egos of pilots. Regardless of the conditions agreed to by crew accepting a job, there is a duty of care to provide a safe service to the public. Fatigue is a risk factor that affects the ability to provide the required safety. This is why it should be a regulatory safeguard independent of contractual arrangements (living in a dream world there I know...)