I imagine it's a "negative liberty vs positive liberty" conundrum.
American libertarianism seems to consistently skew towards negative liberty, which is complete autonomy to anything but without any power or resources. I believe this predilection came from Ayn Rand and Reaganism, and that It now manifests mostly as anarchocapitalist sentiments.
I'm a bigger fan of positive liberty - possessing the resources and power to do what you desire within a constrained system.
Unfortunately we live in a society which provides neither. The amazing results of constant compromise.