From my post: "Marriage fairness (i.e., no subsidies), I'll get behind. Gay marriage, no." In case that wasn't clear enough, I completely support eliminating all subsidies for marriage, and view gay marriage as a minor sideshow to the real issue. (See also my edit.)
I only single out gay marriage supporters because they are being jerks about the issue. Instead of pushing for fairness, they push for unfairness in their favor. Most people ignorantly accept the status quo, having never thought about the issue.
Gay marriage activists are not ignorant. They have thought things through, recognize that it is unfair, oppose the status quo, and still favor an unfair system. "I'm not against corruption, I just want the opportunity to participate in it." Why should I support them?