One other thought. The exaggeration has a very negative impact on some people who really ought to be enjoying their cycling. In the Clydesdales/Athenas forum recently there was a thread in which people were bemoaning how slow they were, and asking why they couldn't get their average speed up towards 20mph. Some of them were quite discouraged. They read absurd claims about average speeds and felt, as relatively new cyclists some of whom weigh 300lbs, that if they couldn't ride at >18mph they must be doing something wrong.

I just finished a tour with maybe thirty pounds of gear on an admittedly heavy bike. That stops one pretty effectively on the hills. I was averaging around 11-12 mph overall, and not dawdling. If I were 100lbs overweight I'd be proud to be able to get up any hills at all, let alone average more than 15mph for a two-hour ride.