I think there is a balance between pure libertarian-ism and the nanny state. I like the way Jeffrey Holland put it as he spoke about serious moral laws,
For example, parents have to exercise good judgment regarding the safety and welfare of their children every day. No one would fault a parent who says children must eat their vegetables or who restricts a child from running into a street roaring with traffic. So why should a parent be faulted who cares, at a little later age, what time those children come home at night, or what the moral and behavioral standards of their friends are, or at what age they date, or whether or not they experiment with drugs or pornography or engage in sexual transgression? No, we are making decisions and taking stands and reaffirming our values—in short, making “intermediate judgments”—all the time, or at least we should be.
When we face such situations in complex social issues in a democratic society, it can be very challenging and, to some, confusing. Young people may ask about this position taken or that policy made by the Church, saying: “Well, we don’t believe we should live or behave in such and such a way, but why do we have to make other people do the same? Don’t they have their free agency? Aren’t we being self-righteous and judgmental, forcing our beliefs on others, demanding that they act in a certain way?” In those situations you are going to have to explain sensitively why some principles are defended and some sins opposed wherever they are found because the issues and the laws involved are not just social or political but eternal in their consequence. And while not wishing to offend those who believe differently from us, we are even more anxious not to offend God, or as the scripture says, “not offend him who is your lawgiver” —and I am speaking here of serious moral laws.
But to make the point, let me use the example of a lesser law. It is a little like a teenager saying, “Now that I can drive, I know I am supposed to stop at a red light, but do we really have to be judgmental and try to get everyone else to stop at red lights? Does everyone have to do what we do? Don’t others have their agency? Must they behave as we do?” You then have to explain why, yes, we do hope all will stop at a red light. And you have to do this without demeaning those who transgress or who believe differently than we believe because, yes, they do have their moral agency.
("Israel, Israel, God Is Calling", Jeffrey R. Holland, Jan 2012)So for everything that is not a serious moral law, we need to give as much liberty as possible. For serious moral laws, such as marriage, we must tread lightly and civilly in the scope of our laws. We have to address the negative effects that breaking such natural laws has on our society.
Breaking serious, moral laws are, perhaps, like the opposite of a public good. The public can have serious, individual harm when society chooses to break them.