When you look at it in a basic manner airplanes now are so reliable that hardly anything goes wrong, unless you fly in a 3 rd
world country perhaps. That said most airlines count on their flight crew to perform well "if everything keeps working". So in order to keep the economics of the business first we have to take a calculated risk, while of course telling the public that safety is first. So as long as everything goes right, fatique is just a calculated risk that we have to accept to keep the beancounters and the share holders HAPPY. IF the **** hits the fan and things do go wrong we have PILOT ERROR to put the blame on the individuals . I sometimes have that nasty feeling in a take off when I'm really naggered, V1,.....rotate......etc, etc, thank god!!!