A boy at my sons school died having fell of his bike and hit his head on the kerb, it was implied at the time that a helmet would have probably saved his life.
As for comparing cyclists with helmets to SUV drivers, its not a very good comparison, polystyrene hat versus three tonne off road, driven by the kind of people that buy three tonne off roaders, they arent like cyclists and personally my little hat gives me no additional confidence, I have many other vulnerable body parts that I would prefer not to hurt so I avoid falling off or crashing just as much.
I have hit my head on concerte as a kid falling off my bike, it hurt, I lost a chunk of skin and hair, I was concussed, at the very least I would have kept the skin and hair (it did grow back).
I fully support any other cyclist who chooses not to . I wear one, its your choice, I partly also wear one so my kids see it as normal as I would prefer that they wear one, debateable or not I do not not want to repeat that head on concrete moment again, my vision went briefly, I could smell phantom smells and it was scary, it would still have been unpleasant with a helmet but not as unpleasant.
Sometimes I think some people dont wear them cos they make you look a goon, true, but, the rest of my ensemble hardly suggests otherwise. I think some spend all the money of the bike and never get round to spending 70 quid on one.