Don’t ask why the author told you something or had a character do something; ask why a character told you something or what the character’s motivations actually were rather than what they were intended to be or, worse (and barf), symbolize.
Suppose I write a book in which a character spends page after page talking about whaling, or their pet political philosophy, or the history of plumbing. There are several ways I can defend having done this from the charge that no one is interested in hearing about that:
- Denial – arguing that actually my particular audience is interested. Most effective for political rants. A perfectly reasonable defense, but leaves readers not in that audience unsatisfied.
- Explanation – giving my own reasons for having done this. Like, I really need the reader to understand the minutiae of plumbing in order for later parts of the story to make sense. Maybe it’s not a good enough reason, but hey, at least I had one.
- Cheating – “But it’s what the character would do! It’s deliberate!“
In very short, my position is that if my story is being told by a character who would spend multiple pages describing plumbing, then I have chosen a boring character who should not be telling a story. Or, if I’m convinced that my character is interesting, maybe I shouldn’t put a bunch of boring words in their mouth, since probably an interesting character would be saying or doing interesting things instead.
To put it another way, saying “it’s what the character would do” is a general excuse that can justify anything. The reason it provides no actual justification is simple: yes, the space of possible characters contains the character as written, but it also contains a version of the character who wouldn’t say something so boring/pointless/verbiose/etc. I have to justify why I plucked the former out of character-space and not the latter.
Perhaps the character that rambles on is a more parsimonious character, e.g. if they’re often inclined to long plumbing discussions, maybe dropping this particular plumbing discussion would be out-of-character. In that case the question becomes “Why does my work need this character? And why has it failed to convince the audience that it does?”
Aside: what’s wrong with characters’ actions symbolizing things, anyway? I’m pretty sure that’s like Literary Fiction Traits Top Five: characters doing things because it’s symbolic of something. Their “internal motivation” is back-written to fit, if it really fits at all. The standard of literary fiction is how far backward an author is willing to underbuild, no matter how empty-feeling and disconnected it becomes. But that’s a different rant.
This habit of saying “but I’m deliberately choosing to do this” extends throughout all of fiction. Maybe you deliberately don’t answer questions. Maybe you make characters deliberately obnoxious; not merely evil, or even unlikable, but deeply unpleasant to experience. Maybe you deliberately use clichés; maybe you deliberately avoid clichés. Maybe your ending is deliberately unsatisfying or deliberately deus-ex-machina. There are limitless possibilities.
But on the whole, being deliberate isn’t sufficient in my mind. I don’t think I’ve ever changed my mind about liking anything on the basis that it was deliberately chosen to be exactly the thing I disliked. What am I even supposed to say to the claim that it was so? “Good job making me not like it”?