Kind of like when they bring up Pascal's wager.
The way I see it is like this:
There's probably 10-20% of the population that actually wants to know things. The problem is that knowing things is hard work. Knowing one thing usually means you have to find a bunch of other things out first. And then, when you do, it isn't neat and tidy. There are all kinds of complications and conditions on that knowledge. It yields answers like "in X% of people with condition Y, Z can have effects A, B, and C". The plus side is, when they know that, they know it well. They want to know the lower case "t" truth.
Another 70% or so of the population just wants to be told what to believe. They don't want to have to do any work. They don't, and don't want to, understand what "in X% of people with condition Y, yadda, yadda, yadda" actually means. They want to know, "is Z good for you or bad for you?" They want to know the capital "T" "Truth"
The last 10-20% is comprised of the people who want to be in power. They play on the second group's desire for capital "T" "Truth" by taking enough of the lowercase "t" truth to make it sound good, spin it with whatever the flavor of the month is (morality, security, fear, etc) and feed it to the second group as capital "T" truth.
When the first group (let's call them "seekers" for convenience) find a problem in the third group's (let's call them "priests" although they don't necessarily have to be religious leaders) statements, they make an effort to correct it, except that the second group (we'll call them followers although they need not be religious followers) doesn't understand it and so look to the priests for clarification.
The real problem is that the priests desire for power means they aren't necessarily interested in lower-case "t" truth. If they have an agenda, the upper-case "T" truth might be an outright lie. If the lower-case "t" truth goes against their agenda, the followers never hear about it. Usually, though, it's just enough lower-case "t" truth so that, in case someone with a rudimentary understanding actually does check, they aren't caught in a complete lie.
I think this explains quite a lot about the persistence of these fallacies. A priest with a religious agenda introduces the followers to the Watchmaker argument. The followers swallow it whole. The seekers tear it to shreds, but of course, the followers never hear that part. So it just keeps going and going and going. The followers who do hear the refutation ignore it either because the priests told them it's wrong or because they don't understand it.
This is especially true for fallacies dealing with evolution. Evolution is fairly complicated and to really understand it requires at least a cursory knowledge of several different disciplines. The priests exploit this by misrepresenting what evolution really says, and then giving a simple, clear, capital-"t" Truth the followers can repeat over and over again. I've long said the people who disagree with evolution don't have the slightest understanding of what they are arguing against.
As long as the followers outnumber the seekers, I don't see this changing any time soon.
Of course, this is all just speculation and I might be wrong in a number of places, but it makes sense at least on the face of it.
