I don't think most of the opposition to gay marriage is about homophobia. There are other issues at stake. My issue is that it should be a matter for the states to decide. You may disagree but that doesn't make me a homophobe if I oppose the SC's ruling. It's also legitimate to oppose gay marriage if you believe that the institution of marriage will be diminished by it. Doesn't mean you're homophobic if you take that position. A lot of people think marriage is about procreation and to give the children a stable environment. That doesn't make you a homophobe. There are legitimate differences and we should respect all of them as long as they're not based on hate or the desire to force your will on others.
The entire opposition to Marriage equality is difficult to explain without bigotry and narrow religious orthodoxy neither of which should be respected in any way by the law. A marriage is nothing except a legal construct, it is up to the people getting married to diminish it or glorify it and make of it what they will. Jealousy, infidelity, dishonesty, distrust, money or the lack of it, sex or the lack of it, these are the things that diminish marriage, not if the two guys next door are married.