Making Things Civil

The matter, currently before the courts, of whether or not registrars with moral objections to homosexual activity should be compelled to perform civil partnership ceremonies need never have arisen, and need not arise in future. Civil partnerships should be made available to any two unmarried persons who are either of opposite sexes or too closely related to be able to marry each other. Such partnerships already do not need to be consummated. So why should they be restricted to same-sex couples?