People want some sort of moral order. A way to be virtuous. When libertinism does away with traditional morality, you create a vacuum for a new religion to fill.
There are four questions a worldview must answer:
1. Origin.
2. Purpose.
3. Morality.
4. Destiny.
Where do we come from, why are we here, what should we do, and where are we going?
In the West, these used to be answered by Christianity. We were created by God, our purpose is to be in relationship with God and each other, our morality is defined by our God-given value and the example Jesus set for how we should treat each other, and our Destiny is to be found in eternity with God.
There are
consequences from removing that basic framework from the culture. One of them is not just that 'something else' will come to take its place, but that
literally anything will come to take its place.
Intersectionalism answers all four questions as well.
1: You were created from nothing but dust, and are defined by the sins of your ancestors. If you're white, all the evils in the world were perpetuated by your ancestors, if you're anything else, your ancestors were perfect idealistic people that lived in harmony with the world and their neighbors.
2: Your purpose is to overthrow the evil society we live in.
3: Anything in service of The Cause is right. Your value and worth is defined by how useful you are to the Cause. (Possibly based on the color of your skin.)
4: Your destiny is to live in the perfect utopia we will create once the Patriarchy/Capitalists are overthrown.
This is a very compelling ideological framework, because it's self-serving, and it also accounts for guilt.
Secular Libertarianism has no framework for human value or morality
at all. This makes it naturally weak to
any worldview that has a framework for morality. Because the libertine Libertarians decided in the mid/late 20th century that the Christian Conservatives trying to exert even
social pressure on them to live moral lives was intolerable, many of them decided that Conservatism was the enemy of Libertarianism.
Of course, come the 2010's they finally started to see what it's like when people who have 'by any means necessary' ethics gain control of societal institutions and enough government institutions to start throwing their weight around.
Suddenly, the Conservatives didn't seem so bad anymore. We'll argue with you, not un-person you.