The moral or noble aspect is championing fairness and justice for all people not just single sex couples. Benefits for all or benefits for none.
I hear the "noble" part loud and clear, CM. But moral for me implies some sort of standard typically derived from an insititutional religious source, and I don't see that at all. Do you know of any major religious institutions that support abolishing the rights and privileges afforded to married couples by the government?
I think the argument we inevitably see in the "marriage" issue is not one of moral versus immoral, but of
moral versus noble. Those arguing for continued government sanctioning of marriage either have a vested personal interest or a moral compunction borne of religious conviction. Those arguing for the "wall of separation" are seen by these folks as "immoral", not noble.