Nicely argued Gabe but what is really at stake here is a philosophical underpinning. The problem with your argument is that it is for the most part nothing but received wisdom. The summary of which is: It costs more to give medical attention without a helmet than with - therefore, bad.
The question is, is society organized on the basis of how much any particular activity costs? Well, yes and no and for most Americans who are constantly told that money is the only good, they can see no value other than this. Are we willing as a society to allow freedom to others and accept that there are costs associated with that? After all, by your argument if they banned motorcycles completely on the same grounds as helmet laws, you would in the name of consistency have to defend this ban, no? Lets face it, motorcycles are statistically more dangerous than cars and a minor spill on a bike is going to increase the cost to society (measured by medical dollars) than a similar accident in a car (all things being equal).
I wear a helmet and would not do otherwise, but I see no reason to force that on others. Everytime a particular group does not understand the practices of another group in society, The option seems to be to ban that practice. And in the case of motorcycles they generate a lot of fear in people because of precisely what they are not - several tons of steel cage that makes the driver feel omnipotent. Anyone who rides motorcycles must have a death wish right?
Probably minime posted this to be controversial, but I find it far more worrysome that a web site devoted to motorcycling would find it objectionable that some people would choose not to wear a helmet.
I still think we should ban Harleys though on grounds of aesthetics and bad engineering. NO MORE LOUD PIPES Please!