To me, the definitions and defining differences between being tired and fatigued are clear.
Tiredness means that you can have a good sleep and feel readily mentally and physically refreshed.
Fatigue means that you sleep and when you wake you still have a mental haziness like a 2 day hangover and a physical lethargy like you ran a marathon the day before. No matter what rest you have had recently, fatigue is still present. Pilots ARE flying fatigued and micro napping at the controls during critical stages of flight!
Sadly pilots state fatigue and want more money and I agree, more money is the answer!! The more the salary increases, the more pilots will come and ease the pressure on those currently flying.
J