Libertarians get upset about everything. This makes them pretty much everybody who perceives their ox is being gored, or their dogma run over.
I've never known small-'l' libertarians (like myself) to get upset over everything, nor anything practically approaching everything. What's actually happened and accumulated over the years is the discrediting and demonization of the one political philosophy that, if implemented, would prevent the US from inevitably collapsing under its own weight. That philosophy is "the government we need to protect civil rights and institute necessary regulations, but not more than that, and whenever possible actually using federalism and having this government come from the local and state levels".
People can cry about "no true Scotsman" while contributing nothing if they like, I don't care, after all that is one of the currently trendy fixations or memes on this site, though its implied promise of instant effortless slam-dunk "victory" never seem to materialize. But I've never seen a self-described small-'l' libertarian who was an anarcho-capitalist (e.g. you get only the police protection you can afford to pay for, and other rubbish notions like this). I've seen plenty who recognize law enforcement as one of the legitimate functions of government, with the goal of preventing people from using force/fraud to deprive others of their civil rights.
I've seldom met one who didn't recognize the vast wealth disparity as a problem, and reasonable regulations as a method of preventing it from getting out of control. You can't have anything even slightly resembling a free marketplace if a few major players can trample little guys (keywords in that sentence: slightly resembling).
I could go on and on, but the point is simple: there is a certain spectrum of libertarians I've actually observed because I was honestly interested and took the time to look and learn about it... then there are these imaginary "libertarians" someone periodically rails against on this and other sites. The problem is, I've never actually witnessed the latter. The closest I've encountered were genuine anarcho-capitalists who had libertarian sympathies, but they didn't represent themselves as libertarians, they (correctly) called themselves anarchists.
The whole thing smells of a smear job. It's standard PR practice. If "you" are the major political parties and the entire power structure built around them, so you have a lot of power and wealth to lose and want to protect it ... and then something goes against your interests, and it actually is a good idea with no serious logical flaws so you cannot attack it on those grounds, you don't just give up there. You simply can't let this idea catch on, as it would drastically reduce your own size and power. Standard practice at that point is to use FUD tactics, lie, misrepresent, whatever it takes to discredit this idea that, if implemented, would harm your position. With the current media apparatus, it really isn't very hard for monied interests to do this.
So that establishes both motive and capability. It's a smear job. Implementing anything resembling libertarian thought would mean the single largest transfer of power away from the federal government and towards the states and the people. It just can't be represented in a favorable light.