When you want to make a tremendous social change like this, the burden is on you. Not us. Tell us why SSM is good, don't demand we tell you why it's not good. We're fine as it is. We don't have to do anything. You do.168,835 posts later, and not one good argument against gay marriage.
I hope you understand this simple concept, but I doubt it.
Before you file hate crime charges and have a self righteous fit, I'm OK with SSM. I feel no need to tell you why. Same as people who are not OK with it should feel no need to tell you why.
Hope that helps!