Why do writers of fiction who employ "far-fetched" overall plotlines, "sweat the details." In other words, when writing a somewhat absurd historical novel in which the overall plot could never - or seldom - take place, why bother to get the tiny things historically accurate?
I'm also a writer of fiction (though most of my historical fiction is based upon actual figures, and thus this problem of "far-fetching" overall plots is void, as they are already written in the annals of history) and I think this is all a result of inspiration.
Once an idea pops into a writer's head, the impulse to write it down is nigh irresistible. Thus, even a "far-fetched" plotline comes into existence. However, the writer has an overall desire to do justice to the history, hence "sweating the details." As the details were not conceived in the initial moment of inspiration, they remain to be written, so the writer retreats to historical context.
Also, when one has created a plotline, one does not necessarily stop to analyze how accurate it may or may not be, before one tells others of it. Rather, in the haze of inspiration, the writer thinks, "Brilliant! A plot!" and moves forward with the project. It is entirely possible that the writer is completely unaware that the plotline may be "far-fetched" until sitting down to tell outside readers of it.
In addition, when a writer starts at his craft, the point IS the story. This means that everything aside from the story is secondary to it, but the story must be told. If the story is unlikely, too bad. It needs to be told (hence, I believe, the high degree of affection for the fantasy genre, where you can write a historical novel without having the rely upon the bonds of what truly occurred). History can help an author along, however, and a writer may well be overjoyed to think his work might actually lie somewhere within a sphere of reality or something approaching it. History is history, and it's already been written, a writer might say, if you want history read nonfiction. I'm here to present a particular story...or something along those lines.
Of course, there is the general league of those who are simply ignorant of the past, and therefore couldn't tell if their story fits in the real, historical context or not, but that is a wholly different sort of person.
The spinner of tales who bothers to try to make things right, historically, is trying to be conscientious. That person knows something of the history, and does not wish to subject it to entire falsehood. Therefore, the author does his best to make it accurate, true to life. A lover of his tale and of history. And then he sometimes gets rebuked for trying, because the tale was "far-fetched" to begin with.
"Fiction is obliged to stick to possibilities. Truth isn't."
-Mark Twain
-Mark Twain