Well, fair that, yeah.
If I may offer the perspective I held back when I was a Christian: there was a time when I would've classified myself with the Religious Right on many issues. I was considerably more conservative than I am now, by leaps and bounds (though moderate on some issues too). While I don't ever recall being rabidly homophobic, I took the stance that homosexuality was not even remotely Biblical, and adopted an attitude of pity that some would live in sin that way - a "hate the sin, love the sinner" way of looking at it.
However, I should also note that I knew absolutely nothing about GLBT anything. I'd lived a very restrictive, repressive, sheltered life, and for most of my life homosexuality was just something no one ever talked about, for good or ill. So gay marriage as a specific issue never even came up at all, back in the day, because homosexuality just wasn't even on the radar until I was nearly grown up.
It wasn't until I was in college the first time and a good friend of mine came out of the closet that I got any real education on the subject. I will be forever grateful to that friend for being willing to sit down with me and answer all my stupid questions, because it put a face on something that, even though I didn't find it repulsive, per se, I just didn't know anything about it at all.
I do recall a level of fear in my religious community about homosexuality. For some it was simply an unknown, for others it was a frightening threat, and becoming truly educated about it was equally frightening. It didn't occur to me why, for a long time, but I just had a thought about it: look at me now. I am not gay, but I am polyamorous, generally liberal, and my sexuality had taken some very interesting turns over the past decade or so. My values stand 180 degrees from most religious conservatives now, and becoming educated was part of that shift in values.
One cannot adopt a new idea if one has never been exposed to it. If one cannot avoid being exposed to new ideas, vilification of said ideas is one way of warding them off. I've found over the years that the truly bigoted tend to be resistant to honest education; willful ignorance is part of the way they preserve their deeply-held values.
Someone ignorant but open to education may be able to see you as human. Someone hell-bent on preserving their beliefs at any cost probably will never be able to.