Why don’t they just pass a special bill that applies only to unions between persons of the same sex and leave the laws pertaining to marriage men and women intact?
They have done that in many places. I imagine you never heard to ‘Civil Unions’. That wasn’t good enough anywhere it was tried and the gay lobby continued to push for ‘full marriage equality’ even in the face of such laws.
Better that the state simply has no part in marriage whatsoever so the heavy hand of the state not be used against those who only want traditional(real) marriage.