This is a widely believed assumption, but do you have any figures to back it up?

Consider that most bike crashes happen at slower speeds, and cyclists are often thrown clear of the wreckage. This can be very painful, but who knows, maybe less lethal.

Also, most injuries in car crashes result from the person being slammed against a part of their own auto. Far from "cradling" them, the auto then becomes the weapon that injures them.