While the policy conclusions of libertarianism are often quite sound and reasonable, there are some major holes in the philosophy's foundation. Even the idea of the sovereign individual isn't all that true. The separation between people is apparent, not actual. In reality, we all live our lives within a soup of electromagnetic radiation that interpenetrates the apparent boundaries of matter. The perception of separation requires a function of the human mind that identifies and categorizes patterns. Without this function, we would not be able to delineate boundaries in our environment.
The pervasive belief in individual sovereignty does very little to liberate society. Once we declare the individual to be King, and many individuals to be many kings, we have created divisions where there are none. We've cut up and scattered our power -- not only in a non-unified front, but in a lack of truth. Power requires truth; and what's a movement without power?