The danger is that if commands were allocated at the management's discretion then it would be the brown nose brigade who would get rewarded for their efforts.
The ones who always take minimum fuel irrespective of the weather on the day. Those who volunteer to work on days off for the money, even though they are breaking agreements by doing so, those who we used to call the Martini pilots who would go anywhere, anytime, anyplace.
In short you could write off any hope of a home or social life because you would have to scramble up the same slippery pole. The advantage of the present system is that pilots still have to pass the standards laid down by training departments, rather than the managements favourites getting the job.