Libertarians have a moral vision of a society that is just, because individuals are free.
This vision is the only reason for libertarianism to exist. It offers an alternative to the forms of political thought that uphold the power of the State, or of persons within a society, to violate the freedom of others. If it loses that vision, then libertarianism becomes merely another ideology who policies are oppressive, rather than liberating. We expect most people to be inconsistent, because the beliefs are founded on false principles or on principles that are not clearly stated or understood. They cannot apply their beliefs consistently without contradictions becoming glaringly apparent.