As somebody who, over a 15 year period, cleared up a fair few dead motorcyclists after they had collided with vehicles/walls/bridges etc etc, I can confirm that motorcycling does seem to be slightly riskier than flying a light aircraft (OK, to be honest, its a hell of a lot riskier!!!)
I think insurance companies penalise pilots with higher insurance premiums because they are allowed too! Greedy chaps indeed..