The label was colonized by Birchers, AnCaps and other Koch fascists in the fifties, so it’s no wonder that people get sucked into it without realizing that the contents don’t match the box.
Among others at the Foundation for Economic Education, in 1955 Dean Russell urged followers to call themselves libertarians, which was claimed to be an obscure and unused term.[1]
[1] Rothbard, Murray (2009). The Betrayal of the American Right. Mises Institute. p. 83. ISBN 978-1610165013. Retrieved 10 November 2019. “One gratifying aspect of our rise to some prominence is that, for the first time in my memory, we, ‘our side,’ had captured a crucial word from the enemy. ‘Libertarians’ had long been simply a polite word for left-wing anarchists, that is for anti-private property anarchists, either of the communist or syndicalist variety. But now we had taken it over.”