False dichotomy. Just as the law doesn't totally ban people staying in apartments that they don't rent, it doesn't seem necessary to totally ban motorcycles. Motorcycle helmet legislation, while rather lenient in the US, still deals with this specific security risk. (And no, I don't think this is a particular infringement of personal liberties, considering the medical costs that often have to be born by the tax payer, never mind the trauma for other participants in the accident)