In the words of one its authors:
"We have no government armed with power capable of contending with human passions unbridled by morality and religion. Avarice, ambition, revenge, or gallantry, would break the strongest cords of our Constitution as a whale goes through a net. Our Constitution was made only for a moral and religious people. It is wholly inadequate for the government of any other." -John Adams
See the problem?
Government cannot make people moral. Even compelling outwardly moral-seeming behavior cannot make people moral. Rather, much of the immorality in society is in significant measure a result of government action.
Those who would equate libertarians with social liberals should note that libertarians strongly oppose much of the government-sponsored indoctrination put forth by GLSEN et al. While libertarians would not outlaw homosexuality, nor would they have the government promote it. IMHO, that's a very good position between the liberal and conservative extremes.