I have also seen a great deal of fury at North Carolina for passing a foolish law. I have several thoughts on this too.
1) Most states have such bans in one form or another. Very few states have legal recognition of basic human rights irrespective of sexual orientation. That North Carolina did not have a formal ban could be characterised as an aberration. It's one of the stronger holdouts against such rights based on demographics and polling data and essentially just hadn't gotten around to it. (by contrast, Maine is one of the strongest states in support that hasn't done so, and Iowa is a clear outlier thanks to a few judges). In my mind this means that other than a bunch of states in the NE US, few people have a leg to stand on here to see these NC voters worthy of extra derision and scorn. Pot meet kettle.
2) Most voters do not fully understand what they are voting on in elections, especially local elections. First, North Carolina already did not recognize same sex unions under their civil unions/domestic partnerships, so the legal change was unnecessary for the reason supposed that it was. Second, there's some evidence that over half of the population in NC favored providing civil unions to LGBT residents and affording them with equal protections, just that they didn't want to call that "marriage" I suppose. I think this is the wishy-washy position of most Americans that results from having very few attentive thoughts to the actual issue. Indeed at this point I'm far more comfortable logically and rhetorically with people who say that they shouldn't have those rights at all. At least they're being consistent by acknowledging their bigotry and intolerance rather than suppressing it into a socially approved but mostly useless gesture.
3) I would guess the timing of the vote coming as it did near a conservative party primary did not help the voter turnout, but I doubt this affected the outcome, just the margin. Evidence suggests also that people/voters who support do SSM, or even just same sex rights, are not as likely to be highly motivated to turn out to vote on the issue either. Given that there are not that many homosexuals, who might have a direct interest in the outcome, I don't think this is that surprising. There are plenty more religious and highly motivated people who always vote. Especially outside of the NE US.
4) To me the closest parallels to these sorts of votes is watching them in relation to Prohibition. Interracial marriage may be the closest in the actual rights and practices afforded to people that were previously being denied, but that cause advanced in a much more roundabout way. With several states abolishing bans very early on in post-colonial history (Pennsylvania for instance) or having no laws in the first place (New York or Wisconsin), and a few more in the civil war/Reconstruction era and/or some shortly after statehood (Kansas, New Mexico). The issue was routinely a strong campaign attack ad during the antebellum era and the Civil War elections, and was involved indirectly for Prohibition's political support within the South especially. That left a bunch of holdouts that took decades more to resolve (beginning after WW2/Korea most of the American West abolished their bans), including all of the ex-confederate/ex-slave states that didn't abolish their bans until a Supreme Court case nullified them. That's a very different path to equality to what we are seeing now. Here's what I think is happening instead.
a) There's a very strong growth toward permissiveness or tolerance of homosexuality and homosexuals. This has happened very fast, over the last 15-20 years. Keep in mind that Clinton signed off on DoMA not that long ago. Keep in mind also that overturning state laws regarding bans on sodomy was even more recent.
b) There's a very strong reaction to that growth on the part of people who oppose either. Prohibition in both directions (support or opposition) emerged as a very strong national issue very suddenly, after a several decade period of running beneath the surface or emerging in a few local or state considerations.
c) The portion of people who oppose either is still demographically significant enough to do something now or very recently but will not be, in most cases, within about 10 years. Prohibition was enabled by a similar window of opportunity that was rapidly closing from immigration and urbanisation/industrialisation. Indeed, in that case the dry political class held off redistricting alignments for almost a decade in a blatantly unconstitutional action. Mostly so they could impose and enforce their views through control of districts that were more rural and populated by the more "traditional" American citizenry than huge influxes of Eastern Europeans and Irish/Germans but which were no longer representative of the actual population in most states.
d) There's a very strong set of battles over "side" issues like education, through curriculum and textbook wars. Prohibition was fueled in part by a lot of unrealistic fear-mongering over the supposed dangers of alcohol consumption being in the only approved texts to be used for many schools. Similar fights concern the supposed dangers or the parameters of homosexuality (as opposed to real dangers, such as rates of STD transmission that required a strong educational campaign from within the LGBT community to bring in line, or persistent and meaningless fights over "it's a choice" versus "biological causes". There are likely significant biological causes for people to become murders or psychopaths. If "we" think something is wrong and harmful, this is not an excuse permitting behaviors that are wrong and harmful. But it is then incumbent on "us" to show clearly that it is wrong or harmful in some way. In this case, advocates against gay marriage equality have failed to do so). There are also other sub-battles concerning adoption policies and the like (very similar to Prohibition's eventual involvement in immigration constraints).
e) Both fights were dominated and fomented by religious zealots. Interracial marriage as an issue was fomented by racist segregationists, with religion playing a side role in most cases. I suppose one could put more blame upon women for starting the temperance movements and especially for the textbook garbage, but in truth, it was when men too took up the cause that it started to go somewhere (though partly because women couldn't vote for a lot of that time), and it was when women took up the cause of repeal that it started going somewhere too (partly because women could vote at that time). Generally perspectives on alcohol use and homosexuality do or did not have a strong gender imbalance. They do however have a strong religious function. When this guy shows up as a temperance leader, it's hard to see a strong secular basis being applied to the law.
f) Finally, unlike on interracial marriage, Ohio is not fairing so well on either of these causes. It's essentially the median US state for being against recognizing gay marriage right now, including already having a constitutional ban, and it was the hotbed flash point for the cause of Prohibition. It did reasonably well as it was among the last states during the Reconstruction era to abolish interracial marriage bans, which put it, if not the vanguard, at least ahead of the curve politically and morally. This is not an important data point to the overall argument, but I think it shows that there's some different factors at work causing the problem than those involved in more directly related rights like marrying someone who has a different ethnicity.