There’s a reason marriage is what it is, everywhere around the world. It’s not about religion; it’s too universal, too widespread among too diverse religions, for that to be the main issue. It’s not primarily about the moral status of certain sexual acts, although it is partly that. The ancient Greeks celebrated homoerotic relationships but they never confused them with marriage. Marriage is what it is because no other relationship expresses such a comprehensive private union with such a fundamental public purpose.It is on this basis that Tom claims to reject same-sex marriage.
I think that Tom's paragraph contains some true statements, but marriage is not about public purpose, nor is public purpose reflected in civil law about marriage. Marriage is about property.
Marriage law dictates who gets my stuff when I die. It determines how I must share my property with my wife if we should split. It dictates who has ownership of my affairs if I am incapacitated and cannot decide for myself. It determines who has access to me when I'm in the hospital. And, it determines who has parental rights over my children if I can no longer fill that role. These are rights of access, property and control.
Civil law on marriage does not say that I have to breed in order to gain these rights. It does not say that only employed people can get married and reap the tax benefits.
Why was the law written to reflect rights of property and control? Well, it's not because some supra-genius somewhere did an economic analysis of gross domestic product, and discovered that marriage is a good way to optimize it. Marriage law is the way it is because people like you and me won't settle for less! No, if I die, my stuff goes to my wife! If you say otherwise, them's fightin' words! Same goes for my kids. You can't walk into my home and take ownership of my children without sparking a small war, no matter what the law says. The law makes only very special exceptions to these rules.
Now, any argument against same-sex marriage has to convince us that gay couples are not entitled to these same rights of access and control. Of course, no such argument exists among decent human beings.
A side note: I suspect that the tax break for married couples may be a social engineering feature. However, the tax break isn't what this debate is all about. If there were no tax break for married couples, we would still see the same arguments from opponents of same-sex marriage.