As I understand it, there are those who pay their way (first, business class, late walk-up coach class).
Then there are those who don't ($375 round-trip JFK-CDG, but only if you book in advance, non-refundable).
So load factors don't mean squat, and are more of an annoyance.
For instance: this weekend I had to fly over to europe for a maintenance test flight. Hair on fire, be there yesterday, AOG (aircraft on ground) etc. In four hour's notice I got a round-trip business fare for $6000.
The last leg, on the way home, was on a pitifully cramped RJ operated by Pinnacle airlines. Sitting beside me was a woman flying DTW-BHM to visit her daughter. I know from experience that if she shopped early and used the internet she paid ~$280.
Therefore, you could cull her from the list and not make a hiccup on NWA's bottom line, in the grand scheme of things.
The biggest risk is the good people leave of their own accord and you are left with the worst of both bunches!!!
As good a definition of the Free Market as you can get.....