I'm not saying they're the same thing - I'm pointing out that as risk increases, you add safety features. Drivers in certain situations (racing, for example) do wear helmets, as the risk is now judged to be sufficient. A 10mph ride around the block may well be safe - but the 10mph part isn't so relevant - it's the idiot in a car doing 60mph who doesn't look for cyclists that is probably the significant part of the risk. So...