Men's Journal Magazine has an interesting article this issue. They interview 4 Heroic Bike Couriers in NYC. One does stunts for movies. Seems the "experts" still measure their careers in broken bones, teeth and stitches. But then again it is their job to be on the streets 10 hours a day 6 days a week. But they all say its a love they can't get away from.
Maybe that is the answer for the OP. Once its under your skin, you gotta have it.
From an insurance perspective, trauma that results from an illegal or intentional acts by a biker is not covered. If a driver dodges you and hits another car, the biker paying the claim from his own pocket. OTOH, health insurance pays no matter how stupid a person is. In the claims world, "I knew what I was doing, but the idiot reacted the wrong way," is a subclass of claims.