Understanding libertarians as like believers in Immanuel Velikovsky's "Worlds in Collision". In 1950, Immanuel Velikovsky published "Worlds in Collision", a bestseller detailing how mythological events were actually due to interplanetary catastrophes. There is an apocryphal story about a conversation between an astrophysicist and a historian. Both were impressed by the book, and they started talking about it. The astrophysicist said "His physics is total bunk, but his history and mythology are superb." The historian said "I thought his physics was impressive, but that his history and mythology were all wrong". It would be a great story if the two decided then that the book was worthless based on each other's expertise.
We have the same story with libertarian economics and philosophy. Experts in each field think economics and philosophy do not support libertarian claims. Least of all the claims of political and individualistic libertarianism, the popular beliefs promoted by the Kochs.
But wait, cry the libertarians, we have our own experts with high reputations. Nobel laureate Milton Friedman in economics and Robert Nozick in philosophy, for example. But it does not require expertise to observe that Milton Friedman was a propagandist for capitalism and that he did not win his Nobel prize for anything having to do with libertarianism. And it does not require expertise to notice that Nozick starts out with natural rights, a viewpoint ridiculed by philosophers for hundreds of years as "nonsense on stilts". Even funnier are the other economists and philosophers libertarians might cite, such as Murray Rothbard, Friedrich von Hayek, Jan Narveson, Ayn Rand and many others: all of whom disagree with one another. If each thinks the other is wrong, why does anybody claiming to be rational believe in libertarianism?
The answer is, of course, that belief is not rational and usually has less to do with rationality than with values and preferences. Exciting, comprehensible stories sell to the rubes, even if they are blatant nonsense.