The speed limit is 70 mph, the alcohol driving limit is 35ug in 100ml, the tyre thread depth limit is 2mm. Does this mean that driving ALL the time at 70mph, with 35ug/100ml alcohol in blood and near bold tyres is safe?even if it is snowing? even you are really tired? is it just as safe than driving bellow those limits but at an apropriate speed for the conditions, not drinking at all and replacing your tyres sooner?
The limits are just that, limits. They are not designed to be used as the NORM. They guarantee a minimum of safety in specific areas but not if you then ignore all other contributory factors. It may be considered an acceptable level of risk to have a small proportion of low experienced but carefully selcted pilots for shorts periods of time. That does not imply that is equally safe to have large numbers of inexperienced pilots of untested anbilities constantly rotating for sustained periods of time.
If you the add to the mix income levels that preclude the ability to obtain suitable rest we end up with the crash at Buffalo. This is why the FAA is doing a u turn and mandating minimum experience levels in airline operations. As they say over there "safety is no accident".
What really gets my goat is the lame justifications of those that put their own greeed ahead the lives of others.