I understand the value of using labels to mean something specific, but it's also clear that it holds libertarianism back. Like Catholics or Yankees fans, I suspect there are degrees, but the majority are not extreme in their beliefs.
The two big parties at least have the benefit of established social groups that make you feel like you're swimming with the tide. Libertarians don't yet have a central narrative that can withstand the marginalization by the media and polite society, and specifically, viable libertarians run under the name of a major party, compromising or muddying that message.
I like the call here to talking about ideas rather than teams. And I like the point that no one's calling for change overnight. I call myself a (civil) libertarian, but that's an inclination, not a manifesto. I'm not extreme in most of those beliefs. Yet third parties get pinned to the most extreme conclusions of their tenets, while the fringes of R and D are understood to be fringes. We have to overcome that institutional inertia with an occasional bout of critical thinking. Take party affiliations off the ballot.