Water has always been something that I care deeply about, and I'm very aware of its limits on this planet. If we don't change our behavior around water, water will become as valuable as oil. That is a given. When people don't understand that, I'm surprised.
The costs of marriage breakdown are borne by the entire society, and therefore it is reasonable for the entire society to demand support for marriage - to insist that it is privileged both culturally and legally.