Not all laws are are meant to protect people from themselves, most laws aren't.
Murder isn't illegal because we want to protect people from the results of their actions, it's illegal because we want to protect people from the actions of others. (Or, failing to do that, punish the aggressors in response) Surely you see the difference?
Basically, the argument is that people's liberty should only be restricted up to the point of defending the liberty and rights of others. If an action hurts no one other than its actor, the state has no right to restrict them. People should be free to live in line with their wishes and conscience up to the point of not violating the rights of others.
With regard to seatbelt laws, I would ask the same question, as I do think that the seatbelt laws are also paternalism and morally wrong.