Truth and Certainty
I don't know if Exegetical Panic explains why homosexuality gets so much *more* panic than most of the many other things that contradict a simplistic reading of the Bible. But I do think that the risk for a fundamentalist of Exegetical Panic is going up all the time, so it becomes a constant source of stress.
A lot of this is due IMO to the greatest philosophical achievement of 20th-century science: realizing that the quest for capital-T Truth means you have to give up capital-C Certainty. It took a while, but I'd say most scientists are now content with the idea that there are things that are in principle uncertain, that one way to learn is to get proved wrong, and that your ideas about the world are going to change. That's why scientists can face situations like oops, we seem to have misplaced 80% of the universe -- AGAIN without getting terribly bent out of shape about it -- not that it wouldn't be nice to have some answers we all agree about, but it's not a horrible ontological trauma.
But I think I think living in a world like this *is* an trauma for a lot of people. Perhaps 20 years ago I remember reading an article in Biblical Archaeology Review, in which the author was expressing irritation at historical-critical analysis of the Bible, because "what kind of real knowledge changes every generation?" Well, that would be scientific knowledge, actually, where even if new knowledge doesn't sweep the old away, it changes it so it becomes gradually unrecognizable.
For a lot of people the result will be Future Shock. I think this is what a lot of the "culture wars" are about: people who've been trained not to expect the shock of the new, being hit with it wave by wave.