But why does anyone care about the issue?
The reason is that government discriminates -- heavily -- on the basis of marital status. It matters a whole lot to Uncle Sam (and to your state government) whether you're married or single.
When you get married (or divorced), it changes your tax rate, has a huge effect on government benefits, and causes the government to treat you differently in other ways too. In many cases, a marriage certificate means you and/or your spouse get lots of new government benefits. No wonder people want the government to accept their marriage!
But that's all wrong. Government should not discriminate on the basis of marital status. In fact, government shouldn't even know (or care) whether you're married or single.
Marriage should be a totally private affair. If you want to sign a binding marriage contract with another person, feel free. You get to decide the terms of that contract.
Is it wrong for homosexuals to marry each other? For that matter, is it wrong for heterosexuals to marry? What does marriage mean? Those are matters of individual opinion, not state enforcement.
If government stopped discriminating on the basis of marital status, this whole issue would basically go away. We wouldn't need lawsuits and voter initiatives. People wouldn't care whether the government called you "married" or not, because it wouldn't matter. What would matter is what you think, what your friends and relatives think, and what you put in your marriage contract. That's how it should be.