S/he is just like all the other people who engage in electing law makers that create laws that control how we live. Part of being in a democracy like government is that everyone gets a little say in how we all live our lives with a majority rule. Things like constitutions might mean a super majority is needed for some things instead of a simple majority, but the right to have a say is still there.
You're forcing your point-of-view upon others.
Churches have no ability to enforce promises with violence or confiscation. And they shouldn't. So it's important for governments to establish some sort of lowest common denominator and hold people legally accountable.
I understand the impulse to be non-judgmental, but when both laws and the rest of society get out of the business of enforcing marriage contracts, you actually take choices away from people that want a stronger marriage contract. They can no longer enter an enforceable contract that requires monogamy.
We're not adding more choice for everyone that way. We're just choosing (as a society) a different lifestyle.
Isn't that what prenups are for? (modulo the fact that it is sometimes difficult to enforce prenups).
Let's say you like the marriage rules pre-1970 (no no-fault divorce). You can't write up a prenup that resembles that and have it be enforced by the government (reject applications for divorce and applications to marry someone else).
More options and freedom weren't added when each state adopted no-fault divorce. One option was taken away (pre-1970 marriage contracts) and another was picked (no-fault divorce).
Someone might not like with pre-1970 marriage contracts, but who are they to judge someone else's culture and preferences?
A family's structure and agreements is not public, nor should they be. Unless said family choose to disclose that fact by their own volition.