No expert on objectivism but it always seemed to me that those folks were attempting to figure out a way to obtain “The Blessings of Liberty” without the need to invoke God.
That is true to the extent that Objectivism is an atheistic philosophy. In Objectivism the "Blessings of Liberty" are derived from the nature of human existence using a rational process.
Irrespective of the hows and whys of individual liberty and freedom, Objectivists believe in the sovereignty of the individual as the basis of the Objectivist ethics.