So why do crew keep going into discretion?!!
Good question Cpt. Prop! But I'm quite convinced that there is a lot of pressure within the companies to do so. There are only few commanders who have the strong shoulders to proceed as you outlined.
Why are many commanders flying their birds - as requested by the companies - more and more at the recommended max though the coffins corner become dangerously small? Do they just want to avoid the invitation for a coffee at their superiors. It is all about saving fuel, but it is always safe? Well AF 447 has demonstrated what may happen if you have some more factors associated with this. And BTW: while talking "fatigue" and so - how long was the F/O on the cpt. seat in the cockpit of AF 447 when the mess started? Ever heard of "sleep inertia"? - This was at least a contributing factor in another - fatigue related accident: Air India Express at Mangalore...