If your goal is just to finish without getting anything out of it, except a "medal" then that is equally ridiculous.
If just finishing within the time constraints means that I'm not getting anything out of my riding, then I may as well stay home and play X-box for 9 hours. Everyone who goes out and rides a hundred miles in one day is getting something from it; even the people going 10mph with their picnic lunches and camera gear. They're not getting the same benefit as the person who finished in half the time, but don't discredit their effort.
The goal is fitness... As I said, a 6-6.5 hour RIDE time ride is something to strive for... Any speed less is soft pedal, and but for upper body discomfort, you might as well choose some other sort of exercise that doesnt consume as much time.
Your goal is fitness, and your definition of it is far more restrictive than many "fit" people I know. Suggesting people are wasting their time if they're not aspiring to live up to your standards isn't going to win a lot of people over to the sport. Unless I'm doing a century on the track, I have no plans for a 6 hour RIDE in my future. Should I just save myself the time, sell my bikes and give up now?