A few things:
Mean is the sum of all values divided by the number sampled. Median is the value at which 50% of the population is both above and below the value.
I think IQ is done on the assumption that it's normally distributed and centered at 100, with the bounds at 0 and 200.
Hopefully by writing this, I show that I'm towards the better end (above-median) of the IQ histogram
I chose my first bike based on insurance and I think anyone intelligent would. So really, no pity from me if you're young, in a high bracket, and buy a rocket - you just haven't done your homework.
Looking at this the same way as cars, these same guys would probably find insurance ridiculous on a Viper as well. Maybe because a used sportbike is $4-5k vs. $40k+ for a fast car, they figure it would be cheaper?
I feel worse for guys below 25 who would like to ride, but can't afford insurance on anything - even with a good record. That said, for whatever reason, I take fewer risks driving, skiing, mountain biking than I did when I was younger. It's subjective and people grow up at different rates (or not at all), but I could see why my insurance is lower now than at 21.
Insurance is based on rates, claims, injuries, etc. Not to say it's profitless, but there's reasons why 21-year-olds with no riding experience can't insure Hayabusas. Medical fees, potential disability, and tort liability are huge cost driving factors.