The facts on the ground is that marriage is not equal to a means to building a family.
As marriage has evolved from a structure in which a family could grow (the “original meaning”) to an affirmation of individuals’ love and a financial/legal “next of kin”, so too has the “right” to be married. From the opinion:
Indeed, changed understandings of marriage are characteristic of a Nation where new dimensions of freedom become apparent to new generations, often through perspectives that begin in pleas or protests and then are considered in the political sphere and the judicial process.