I do care when social authoritarians want to use the law to prevent citizens from equal access to fair treatment by the government because they find the lawful actions of other citizens objectionable.
If this is actually true then like me you should oppose all government marriage not just gay marriage because all government marriage meets your criteria of what government should not do. I oppose gay marriage only because it extends the divide of unequal treatment among citizens. I see no reason if George is single that he and I should be in any way treated differently by government.
I will start a thread on my proposal for how marriage should work from a government perspective over the holidays when things slow down. But the short answer is I would say there should be no difference in government treatment and it should be a matter of private contracts between citizens. I look forward to debating it with you then.