IMHO once you're over 21 you've got the right to decide for yourself whether you should or shouldn't do something. I think many are opposed to the reduction in personal freedom so that's why they oppose them. Personally, I do ride with one. I've ridden w/o, usually when, before my S.O. got her own helmet I'd giver her mine to wear. I enjoyed the feeling of no helmet, but I didn't feel as comfortable or as confident on the bike as when I did. Just my $0.02.