I tersely spelled out some reasons for rejecting the OTF, but as I have since been reminded that lots of contradictory religions exist (thanks), I will take a moment to explain where and how that matters.
Whenever I see proponents of the OTF, I see people who have taken the kernel of a good idea and some worthwhile observations and blown them way out of proportion. There has to be a German or French word somewhere for this very common form of overreaching more specific than `overreaching'. Lacking a word, I'll coin my own:
Pomoing (poh-moh-ing): the tendency to seize on an idea of relatively narrow utility and deform it into a core, foundational, universally-applicable truth, or, the making of a systematic outlook out of a triviality or truism, the unwarranted bloating of ideas. For example, the truism "scientists are influenced by their culture" often becomes "science is a social construct on rational par with other mythologies" in the hands of postmodernists.
The initial idea here is captured in that all-famous quotation: "When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours." This, like `do unto others', reads conservatively as trivial advice: you, a theist, may empathize with atheists by understanding why you reject other religions. This common quote is justly common: it is very often difficult to convey to those who have had little to no experience dealing with critics of their faith to know what it means to reject their faith. Quite possibly for the first time, they are being invited to think why their story that they survived a car crash thanks to Jesus might not convince an atheist. They are being invited to look at their faith from an `outsider' point of view. But a key word there is `an'. I do not recognize that there is any single skeptical position. If anything, the advantage of the appeal I just described is that it can be understood by an `insider'. Theists do not have to become `outsiders' to understand the problem, just as we do not have to become `outsiders' of evolutionary theory to understand the weaknesses of a particular argument for evolution.
The OTF relies on this observation as paired with an appeal to fairness, but proponents do not seem to realize that they are being deeply unfair to religion. I do not think that anybody accepts that one should step `outside' of science in their sense because many theories have been discredited, or because there are conflicts in the scientific community, or because geography and parenting are important indicators of whether or not you accept consensus science. I think the appeals to fairness and consistency should leave us facing in the very opposite direction: rejecting the OTF and engaging with the arguments in the traditional manner. The nice part about this is that we can capture the importance of viewing Christianity as one of many mutually incompatible religions without overreaching.
At the end of my last post, I asked a question: what would Calvin think of the OTF? It wasn't an idle question. If you are a Christian who believes in the predestination of the Elect and the Fallen world, the fact that your religion is one amongst many is not a surprise. That few have the right faith may not bother you at all. As far as I am aware, nothing about your religion says that it should not appear to an outsider as one among many. Strange then that advocates of the OTF tell you that the existence of other religions discredits your religion. You can reasonably say, "my religion looks like one of many to you? Swell, your point being? We agree about this, and it bothers me not. For chances are that you are not one of the Elect and are not destined for Salvation and understanding. That you and others do not believe as I do does not surprise me in the least; if anything, I would be surprised if outsiders readily understood the Truth and could easily aspire to it, as I understand otherwise."
One can argue against such a person, but the appearance of his beliefs to a skeptic should not itself constitute an argument.
The case is different whenever we look at more common evangelical versions of Christianity, in which it is asserted that God intervenes or has intervened to aid Christianity and that the Holy Spirit works on the consciences of most or all to guide them to Truth. Free will. All that jazz. If a supernatural agency is at work in the Christian sociology of Christianity, then it is surprisingly hidden in the actual sociological details concerning Christianity. Here, the fact that Christian belief is largely a function of geography and parenting is very surprising. To a person who thinks that Christianity is a natural phenomenon, it should not be. I think that this is a very powerful argument against evangelical Christianity.
Notice then that there are at least two possible outcomes of "Christianity is like other religions to an outsider": it is irrelevant to some Christians, and it constitutes a challenging argument to others. So what we can not do is treat the motivations for the OTF as legitimizing it against religions generally, since the observations motivating the OTF are in no way an argument against certain religions. To pretend otherwise is to do nothing more than pomo an important, but narrow, point.
Question: Was any of the above "based on red herrings, special pleading, begging the question, the denigrating science, and an ignorance that [you] can only attribute to delusional blindness"?
Edit 1 (7/27/2011): "I don't know" is not devoid of content. Back when I was young - ok, more young - a trusted adult once told me, in rather portentous tones, that God amuses himself by watching weather forecasts. I had many such lessons in epistemic humility as a child, and it has taken considerable effort to unlearn them, especially since many skeptics use "I don't know" to pretend to some sort of legitimate defense for having, or pretending to have, no strong opinion about something, especially as a fallback in questioning the strong opinions of others. Just as I have been bored by "you can't be certain" for years, I am now bored by "I'm not claiming to know anything," particularly when it is being employed to bludgeon those with strong, relevant stances.
There is a joke somewhere about the weatherman who is always right. Everyday he says the same thing, "today it will be between -200 and 500 degrees Fahrenheit," or something like that. I'm willing to bet that weatherman will always be right, so long as measurement is conducted in the usual way. I'm willing to bet quite highly that he'll be correct tomorrow. But this weatherman is also completely useless. I'm less confident that the weatherman who tells me that today the temperature will be between 75 and 95 degrees Fahrenheit is correct, so although I am willing to bet that he will be correct, I will wager less than what I wagered on the prediction of useless weatherman.
Skepticism of religion is the same way. What proponents of the OTF appear to say is this: lots of weatherman contradict each other, so chances are that any particular weatherman is incorrect. But I doubt very much that proponents of the OTF, the `skeptics', have, by virtue of their doubting all the weathermen, ceased to have any stance on the weather. What proponents of the OTF appear to not understand is that their tacit assumption that the OTF concludes that their opinions about the weather are very - or even significantly - likely. Sure, they may have a reasonable stance on the weather, but these do not follow from the fact that at least all but one of the mutually contradictory weathermen must be wrong. Even were the methods used to argue for OTF valid and sound - and they are neither, where dimly coherent - they fail to legitimize any conclusion which stipulates that those who do not share your judgments are mistaken. If anything, it suggests that proponents should adopt any number of absurd priors, no obvious one of which being favorable to a skeptical conclusion.
Yes, you have positions. You would make wagers. You are a skeptic, not a purist devotee of the empty set.
If Steve says it will be between 85 and 90 degrees at noon, and Tom says it will be between 70 and 75 degrees at noon, one of them is wrong. If you think that Tom and Steve are smart, informed guys, you might think that the interval [70,90] is the only one on which you would bet highly. You might, for a high potential payoff, be willing to wager more on a small subinterval of [70,90], but you probably would not be willing to risk anything substantial for the interval [500,1000] - even were the payoff tremendous, and even if you think that Steve and Tom know nothing more than you about the weather, or that they are morons. Location and climate depending, you may even have decent reason to be most confident in intervals close to theirs in any case.
Skeptics about religion are the same way. They would still be willing to say things like "I'm willing to bet that religion is a purely human phenomenon," even if they felt only 50% confident that this is the case. (I think it's almost always much higher than that.) `Skeptic' is always an incomplete description. Skeptics of religion always have alternatives to religious explanations in which they have varying degrees of confidence. You can't sensibly claim to have evidence against religious explanations otherwise, since you cannot claim any value for p(`observation'|`[religious view] is false'), for whatever instance of `religious view' you like. That being the case, you can't update odds ratios through Bayes' theorem. In less jargony terms, you can't say something like "this observation diminishes my odds on Christianity." If you are able to say something like that, you have some approximation of p(`observation'|`[religious view] is false') in mind. Given that, you are saying things about elements or instances of `[religious view] is false', e.g. "natural selection and common descent following abiogenesis" as opposed to "creation, microevolution, and designer intervention." You are also saying something about the probabilistic relationship between `[religious view] is false' and `observation'. You are saying something about the probabilistic relationship between the world-as-observed and the occurrence of `[religious view]'.
You have to say a lot to even begin to talk about evidence. Assume that you are not an idealized, purely non-committal skeptic. You're not, and if you were, you would suck at everything normally described as skepticism.