I can think of dozens of films where for the reason of making things "clear" so that we may know and understand the characters motivation, we are actually given a weak, forgettable story.
Taking things back to my beloved pulp roots, all we needed to know in 'Phoenix on the Sword' was that the king, Conan, had once been a barbarian. Solomon Kane is a puritan, Tarzan the ape man, the "Thin Man" and his wife like to drink while solving mysteries, John Carter 'of Mars', the Gray Mouser and Fafrhd are "Ill Met" in Lankhmar, are any of Lovecraft's protagonists not some befuddled scholar who just now stumbled upon some maddening relic or knowledge? (don't answer that)-but we don't need to know anything more do we?
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On one hand its the ridiculous Hollywood reliance on special effects over story, but also the tacked on, reaching back to traumatic childhood events that scar our poor hero and he has to spend the rest of the movie dealing with such a far-reaching pain. Same with the recent Conan movie, same with the newly relaunched Spider-man movie. Too much baggage. It is obvious to all the fans of these respective hero's that a film version of beloved story-lines could have been opening weekend gold over the revision "lets explain everything" that the suits give us.
Remember the suits are not artists, they are bean counters.
The making "clear" of a characters past eliminates the wonder and mystery of storytelling, it takes away the needed drama of why people watch/read. The audience doesn't tune in for information - if they did, they would be watching documentaries.
The wonder and mystery is why Harry Potter worked and it's why the original Star Wars trilogy worked. People didn't watch ROME or give Gladiator an Oscar, because they wanted to see what it was like to live back then-it was because of the wonder and drama. As much as I despise and absolutely loathe Avatar it followed the bare bones premise on character back-story too.
I am positive I am not alone in my imagination of what "The Clone Wars" were upon first hearing them in Star Wars, being so much better than what we were given in the latter trilogy.
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All of these display a tendency toward the action tale/movie, but that's what I like. I'm not here to discuss what I don't like/do = period romance pieces on Nantucket island.
In explaining too much to an audience whether film or print, we lose wonder. There is the argument that things need to be understandable and I get that, but no art has lasted the ages that did not make us wonder. Mona Lisa's smile anyone? And without wonder you will never get an art that lasts.