Seriously.
Have you noticed the overwhelming numbers of adults living outside the state licensure requirement?
There is a profound difference between social norms and government law. The 2 rarely coincide.
The social norm seems to be to live together without consideration for government controls.
Whether people wish to have legal recognition of their association(s) is their business. If they decide to do so they must comply with the law. The people of Kentucky have decided that consanguineous associations, same-sex associations, etc, are not legally recognized as marriage. If persons don’t like the law, they can follow the process defined in Kentucky law to have the law changed.