Well-put here, from the Heritage Foundation:
Rather than a natural institution designed to bring the two sexes together around the mutual task of forming homes and raising the next generation of children, marriage has become in some locales a list of temporary bargains between adults that is meant to secure interests and benefits. The result is a less child-centered, duty-based, and future-focused institution. Redefining marriage continues a trend away from policies that focus social resources on children and long-term civil society.
