There's a section in Albert Londres' piece 'The Convicts of the Road', about the Tour de France, and it describes a rider in tears because he has missed the cut-off time at a control. The early Tours were run over stages of up to 300 miles, and were homologated just like Randonees, with a road book stamped at controls.
There was an additional class of riders called 'Touristes Routier', who were essentially out to complete the Tour by finishing just within the time limits. The French public are mainly interested in the competition at the front, and the Courage of those at the back. You still see that at PBP, the crowds turn out for the leaders, and for the back of the field. That's mainly because the leaders are predictable, and the control closing times are known. Riders in the middle complain that the atmosphere they are told about isn't there. If you are a middle-marker the atmosphere isn't a patch on the back of the field.
For those with a love of cycling history, Randonnees are a throwback to the days when the Tour de France had stages of over 400km, and the unsupported Touristes Routier exemplified the true spirit of cycling. It's fossilised sport, you can see the same scenes re-enacted in any Audax as the riders at the back struggle to meet the cut-offs, as Londres described in the 1920s.
The literary tradition which surrounded those Tours are what informs Audax writing, and it's the reason so much gets written. The scale of the adventure makes it a worthy subject. That taste for the epic carries with it the seeds of the Audax conudrum. How far can we dilute the challenge before it loses its grandeur? Audax demands a cut-off time, or it ceases to be epic. It's not simply about riding a long way, it's about beating that ticking clock.
I've got a bit of video of the end of Susan Otcenas being interviewed by Kieron, she says 'The more difficult the ride, the better the stories', which sums it up neatly. I've met Kieron twice, once at PBP interviewing the Indian riders and at LEL went he was doing the piece we're discussing, strangely he went the same primary school as me.
http://www.cyclingrevealed.com/July06/July06_TR2.htm