This is such a silly statement I could not help but reply to it.
Art is like life in general, definetely NOT set in stone. And what is considered great art now, can and will probably be perceived completely different come another generation.
The great thing about art and art movements is exactly this, their rejectal of rules formed by previous generations and a re-invention of them when needed.
Art is Creativity and creativity by nature is fluid, if there are rules they are there to be broken, tested, experimented with.
I sure hope you do not have a profession teaching art, with your statement I think you would be terribly stifling in any situation. I would not want to work with you as a fellow artist, let alone have my art education from someone with your mindset.
Cheers and this has little to do with the rest of the topic, just my two cents.
Rest of the discussion is somewhat useless anyway in my opinion, of course major story-line set pieces will receive more attention than a random shack in the wilds, would be a bit weird if it was the other way around.
I think the car anology I made in my previous post is apt.
There is a difference between the fundamental mechanics of something, and its artistic design.
On the one hand you have the skeleton of the structure, and on the other hand you have what you dress it up with.
You are certainly right in your statements when it comes to the flesh, if you will, of a story, but not when it comes to its bones.
There are just some fundamental constants that have to do with how the human mind operates.
Take for instance Marlowe's law about deus-ex-machina.
Marlowe said that for someone to be shot in the third act, you have to show the audience a gun in the first or second.
The gun cannot suddenly appear without reference in the third act, as that would be a contrivance, it would immediately pull people out of the story.
This can be averted by using another trick, namely showing the audience the gun before the part where it becomes essential to resolve the plot.
This is one of these fundamental laws of storytelling, as I said, its skeleton.
Youre absolutely correct when you say that fashion and insight, or just 'trying something new' mean that art is subject to change.
But, for instance, in sculpting, if you do not take heed of the natural faults in the marble, of pressure points and balance and all that, then it will just crumble at the first gush of wind.
There needs to be a technical expertise, a stable anchor, on which the creativity can then build and add.