Semicolons are nearly always an afterthought. The writer starts writing a sentence, gets to a certain point in that sentence, realizes he wants to say more than that sentence can contain, and slaps in a semicolon.
How do you know that, James? Are you psychic? Are you somehow privy to writers' thoughts while they're writing? Or do you simply believe most writers are too lazy to revise their sentences, and their use of semicolons is proof of that?
And so what if the use of a semicolon is an afterthought? Aren't all revisions afterthoughts?
Even in nonfiction, I don't think I've met a writer who plans to use a semicolon before starting the sentence.
So what? Except for periods, question marks, and quotation marks, I never plan my punctuation before starting a sentence. How can I know in advance what punctuation I will need before I've written the sentence?"
Nonfiction aside, semicolons simply don't fit the style of fiction [yet there they are], and I've never found a sentence containing a semicolon that couldn't be rewritten into better sentences. Because you're the best writer in the world, far superior to the countless accomplished writers who use semicolons?
The problem, I think, isn't really with teh semicolon, it's with writers who don't want to throw away a sentence and start over from scratch. It's easier to stick in a semicolon. But how do you know who those writers are?
I also hate semicolons because at least ninety percent of the ones I see are used improperly, but this aside, to me, it's about writing the best possible sentences, and semicolons are not the best choice for doing this. This is your opinion, and many writers would disagree.