The damage of a bike hitting a person is much lower, but that isn't the only factor. I think there is a disconnect between whether a person on a pedal bike is a pedestrian or a road vehicle. I've seen people ride through crosswalks like a pedestrian even though they are technically supposed to dismount here if you're on the sidewalk. It's harder for a driver to anticipate a bike since they are generally going much faster than a pedestrian (not a great excuse for hitting one though). You can absolutely break the speed limit in a school zone on a bike and I've heard of people getting ticketed for it. On the other hand, I've seen people ride on bike lanes on the road act like idiots. I've quite a few people riding against the flow of traffic even though there is a clear arrow indicating which direction to ride. It wouldn't hurt to have more people aware of the laws regarding commuting on bikes. On the other hand, a license could make it more difficult for the people that would normally rely on a bicycle as a form of transportation. Maybe it's mainly a US thing?