Interesting discussion. While I'm generally in favor of less laws to control our decisions at least helmet laws ( like seatbelt laws ) are easy to comply with and have almost no negatives associated with their implementation.
The article's premise is correct in that there will be an increase of traumatic head injury fatalities that will increase the opportunity for harvesting healthy organs for use by others. However most people do not choose to be organ donors. I would submit that the same people who are thoughtless and selfish enough to ride helmetless generally do not choose to be voluntary organ donors. It would be interesting to have a law that allows riders to opt out of helmet use if they agree to sign up as voluntary organ donors.