Opposition to gay marriage can be rooted in the insidious belief that gays are inferior, but is also commonly rooted in the much less problematic belief that marriage is a procreative institution, not one meant to join couples for love and companionship alone.*
That’s why it’s wrong to stigmatize all opponents of gay marriage as bigots, even if (like me) you’d find unobjectionable the forced resignation of a CEO who used anti-gay slurs, or declared that gays are inferior humans, or sought to deny gays even benefits unrelated to the definition of marriage, like the ability to be on a life partner’s insurance. My position has always been that civil unions are not enough–that gays ought to have full marriage equality. But the pro-civil union, anti-gay marriage faction is instructive. Opposition to interracial marriage never included a large contingency that was happy to endorse the legality of black men and white women having sex with one another, living together, raising children together, and sharing domestic partner benefits, just so long as they didn’t call it a marriage.
Does that clarify the inaptness of the comparison?