People at the extremes tend to believe their difference from the majority is proof of their correctness. Anything supported or believed by the masses is despoiled by its very popularity. It wouldn't be a great truth or world-changing idea if everyone knew it. While such reasoning may be reassuring to members of small groups who rail against the larger world, when you break down the logic it tends to more properly be a refutation of those ideas themselves. For example: Libertarianism.
The concept of Libertarianism is fairly straightforward: the government should not make choices for people; society will be better off if everyone makes their own decisions free of interference or guidance. It assumes that people are the best arbiters of what is in their own self-interest and will choose accordingly - the free market will save the day.
While you can argue about the efficency of the market, whether it is truly free, and get into an econometric debate that has no end, the real problem lies underneath those issues, because the vast majority of people, the vast, vast majority, are not Libertarians. The Libertarian Party has existed in the U.S. for over forty years and has accomplished nothing. It polls around 7% of the population (everyone's excited now because it might gather about 10% support this election). Those numbers show that when people make their choice, they do NOT choose Libertarianism.
So we must ask the question: why? Why are there so few Libertarians in this country? Why is there no great Libertarian country in the world? If people are truly rational, if their choices are in their own best interest and they reject Libertarianism, then it has to be because the idea itself is flawed.
Or - as most Libertarians will argue - people are wrong. Tthe only explanation for the lack of support is that people have not thought it through. They just don't understand. They aren't making the simple and logical choice that would lead to a betterment of their life. Of course, if that's true, if so many people over so many decades are simply incapable of making the correct choice, then the entire basis for Libertarian beliefs is flawed.
Whichever side you come down on, whichever flaw is in play, doesn't matter as much as the simple fact that Libertarianism's unpopularity proves it is impractical.
So why does anyone argue for it? Because it is in their self-interest. If you look at the demographics, it becomes clear. Libertarians are white. Mostly male. Mostly young males. They are the people who suffer the least amount of structural disadvantage in society. Not that they would admit that, but in our unequal society they have it the best. If life is a race, they are the group that has the head start, so it's not surprising they argue against any interferrence that might reset the race, any laws that would reduce obstacle for other people, or principles for organizing a society that involve redistributing the wealth acquired under unfair circumstances. Libertarians are true to their principles and have chosen a path that will benefit them the most, which is perfectly fine, but it's their argument or assumption that what is best for them is best for all that collapses under closer inspection. Society has rejected their logic and by so doing proved it false. For that, Libertarians have no answer. There is more wisdom in the masses than many individuals recognize.