Chesterton once accused the Puritans "Not of having too much morality, but too little." It seems to me that the neoPuritans, those secular busybodies that try to legislate their version of good and clean living, are stricken with the same malody.
It is not that they have a robust morality that provides vision, energy, and purpose to human life, but that they have a weak and feable structure, hardly capable of being principled, ordered, or systematic. In order to buttress up their little morality they attempt moral short cuts, the biggest of which is federal legislation.
Lobbying for laws against all things that they deem bad, unfit, or unhealthy, they seek to impose a grand appearance of their morality, but it becomes, like Bilbo Baggins so artfully said, "thin. Sort of stretched, like butter scrapped over too much bread." It is thin, and thus prone to distortions, corruptions, and ripple-effects that were unintended, but necessarily follow.
NeoPuritans try to take moral short cuts. They want the nation to be better, so instead of convincing every man, woman, and child to be better, they simply legislate away those things they believe are making our country worse. They think that national policy and law make people better versions of themselves because it saves them from themselves.
Law that is made to save us from ourselves, rather than to protect individuals from the aggression of others, is always a false step.
It is a bad beginning due to the fact that these moral systems do not have the depth to account for human reason, freedom, and moral development. They really do view the masses of men and women as incapable of making the right choice for themselves when presented the option, and think that they alone possess the skills, knowledge, and insight needed to make someone else's life better.
Catholicism offers a deeper, broader vision of morality. First, though the natural law is an important component of morality, it is not the whole of it. Virtue, grace, and the activity of the Holy Spirit are constitutive elements of Christian morality, which is properly called "Life in Christ." The hyper focus on moral laws, rules, and norms to the exclusion of virtue, spirituality, and happiness present a stunted image of what it means to choose the good and avoid the evil.
That morality is reduced to law-alone has many potential causes. The main one being, in my opinion, the doctrines of Martin Luther that most attacked the Catholic holistic understanding of morality: total depravity, and sola fide. The doctrine of "faith alone" begun the divorce between being saved and being moral. Morality and faith had increasingly less to do with one another. As that strand of Protestantism grew secular, the result is a liberal Lutheranism of Immanuel Kant's variety, whose entire moral system is reduced to the rule of the categorical imperative.
The doctrine of total depravity attacks the very roots of human morality, which is that deep down desire for union with the Good, for a happy life. If one is totally deprived, then even one's desire for happiness is corrupted, and so too would be one's desire and recognition for redemption.
When we are left with only legislation, having abandoned the virtues, freedom, and the relationship between the natural and the supernatural, we are left with Puritanism in either religious or secular clothing. They seek to rid us of our impurities by making them illegal, by prohibition. Quickly, and with great energy, human persons find a way around these prohibitions because these moral short cuts chafe the soul.
There is no respect of the logic of moral growth and development. Instead, there is only the use of coercion through state-sanctioned violence to bring about whatever "City set on a Hill" the elites think they are creating.
And it never works out like they thought. Just think about what made the '20s so roaring: alcohol was illegal, right?