There are numerous issues at play here.
First, we often treat ‘nanny state’ laws as rather black or white - of course smoking is bad for you. Of course overeating is bad for you. Of course it’s stupid to ride a bike without a helmet. If you take that attitude, then going the next step and saying that the government should protect you from such obvious bad choices is easy for some.
But in the real world, these decisions are not black and white. They are lifestyle choices. There is no absolute moral or ethical principle you can point to that says it’s better to live 80 years on a calorie restricted diet than to live 50 years while enjoying every fatty meal you want. Smoking may not be good for your health, but for many people it IS good for their peace of mind. They enjoy it. Until (and if) they get sick, it makes their lives happier. If you really, really value the sensation of the wind blowing through your hair while riding a motorcycle, then maybe driving without a helmet isn’t such a bad thing.
We trade off enjoyment for risk all the time. I SCUBA dive, fly airplanes, ski, and do other risky things. There’s no doubt that I have shortened my statistical lifespan by flying small airplanes, but it’s a choice I voluntarily made, because a riskier life doing things I love is much more valuable to me than a longer life devoid of risk and challenge.
And the thing is, once we move into the realm of personal values and risk/reward tradeoffs, the government is a terrible arbiter. No one but me knows how much I value skiing, or flying, or sitting on my ass typing on a computer instead of exercising. Therefore, a society-wide decision around any of these is bound to be a very poor tradeoff for many.
Then there is the argument for social vitality. I would argue that a society of vibrant, risk-taking people is healthier than one in which the government manages risk and coddles the people. I think we were a better culture when our frontiers were more dangerous, when our risk-takers took more risks, and yes, when more people died attempting great things. When I look at a country like France, where you are protected from losing your job, protected from poverty, where people demand ‘protection’ from the vicissitudes of life as their divine right, I see a culture in decay. Greatness comes from taking on great challenges and even great risk. Mediocrity in the name of safety is not a virtue.
Then there’s the philosophical argument, which I am most fond of. What is the nature of the social contract between me and my government? Am I born free, to walk through the world in a manner of my own choosing so long as I don’t hurt others? Or am I a lesser being, a cog in a machine to be pushed and prodded into behaviours I didn’t choose for myself?
I believe in the former. I believe that humans are born with inalienable rights. I believe that my social contract begins and ends with me pulling my own weight, earning my own living, forcing no one else to give to me what I didn’t earn (or forcing others to give to a third party), and being a good citizen by contributing my share to pay for those things which society must provide and which I am a beneficiary of. My concept of a good and just society is a collection of free people living in peace and being left alone to choose their own manner of living and dying. Free from birth to the grave.
I flatly deny the state the right to tell me what I must think, where I must live, what risks I may or may not take on for myself, and how I must spend my own time, energy, and money. For once you accept that the state has the right to do these things, you are nothing more than chattel - a resource to be plucked, a child to be coddled by those who know ‘better’ than you, a pawn to be manoevered for the ‘greater good’.
The mere thought is abhorrent.