I can tell you what my husband says - "if I die, I die". "I don't like to wear a helmet" "I like the wind in my hair" "The helmet keeps me from seeing as well"
This is the thing that irks me about people that say "oh its my life I will do what I want with it." I often wonder if these people (such as your husband) ever stop to think, "If I die or am paralyzed for the rest of my life, who is going to feed me, take care of me, bathe me, etc. If I die, can my wife/husband/children provide for themselves without my income? Will they be able to stay in this house and pay the bills? Will they be able to feed themselves?" I really wish more people would stop and have that conversation with themselves before they got on a horse, motorcycle, whatever without a helmet. At the hospital when Michigan changed the law to helmets being optional we were joking that we should start handing out organ donor cards to all the motorcycle riders we saw without helmets.