Agreed: On London-Edinburgh-London I'd made my own route which avoided some climbs I didn't want to do as I was carrying a previous injury, instead taking a more circuitous way. Lo and behold, coming out of Louth southwards, there were four riders behind me. None had a navigation system or map and they'd just followed others all the way round. In the 100 hour group they were on the time limit and just hoped that by getting someone to follow they would make it.
I was nice and towed them my way round until it led back to the correct route, losing about 15 minutes in the process as they were slower. And they never did make it in 100 hours whereas I did.
Having nearly got lost on one of my first 200s I was a fairly early adopter of GPS navigation. I subsequently tackled numerous 200s on which groups of other riders kept taking wrong turns. They would insist on going the wrong way even though I pointed out to them that I had the route on my Garmin. In the end I gave up telling them and just went on by myself. Typically, 30+ minutes later they would come tanking past me again, having ridden the wrong way for 5-10 minutes before realising that my GPS had been right!
One rider did it multiple times. I noticed that he had a GPS so when he caught up for the 3rd or 4th time I asked why he kept getting lost. He told me that he didn't understand how to put routes on his Garmin so he was just using it as a bike computer!