Art is whatever is presented as such.
I can throw in with this to a large degree. But I usually value originality and what you describe, Mefi, makes me hugely uncomfortable. Formulaic anything gets boring quickly, and I used to roll my eyes when people had to read out their essays in class, each with a pre-set theme and structure, going by the textbook. I always preferred an alternative interpretation of the subject material. I didn't do great but got better grades than most, likely because I was in a bit of a backwater Afrikaans school and my spelling/grammatical skills exceeded that of my classmates.
FWIW: In std. 2 a teacher marked my essay down with: "Children of your age shouldn't write like this". I thought this was a definite mixed message, and still think the teacher was being a bit of a retard.
Not that I claim my English is perfect even to this day. I often read my posts here in retrospect and cringe a bit.
That said, I think the difficulty in art is that each piece of art presents something different to be appreciated. There's a universe of different things that qualify something as "art" and that's what introduces the difficulty in people trying to apply reductionist principles in classifying it.
Some art presents beauty, some art presents incredible human suffering to prompt the viewer/listener/reader into action, some art is there to make the recipient reflect on their own behaviour/psychology/struggles/place in the world/etc. Some art is somewhat like a puzzle, leaving you lingering trying to tease the meaning out and rewards you, much like any other puzzle, once you do (or think you do).
Often the more "abstract" art is trying to convey a raw emotion using nothing more than the ferociousness or subtlety of the brush strokes. If it is done well
I do appreciate it. However I think more often than not, it fails miserably and just appears like a mishmash of random paint.
More often than not, you walk into people's homes and find "art" that is merely there to look nice hanging on a wall, to give a certain colour or feel to a room. I don't qualify that as "art" art, yet I still think it fits into the general art category by lending a certain mood or feeling to a room. Then again, so does a blank wall painted a certain colour.
And this is where I come back to the admittedly thorny issue of originality. Is a guy pumping out moulds of ducks and selling them in a curio shop making art? I would say no. Seeing the same knitted-dress Barbie doll covering a toilet roll doesn't inspire much feeling in me, other than total apathy. But then by the same token, if we mass-produced perfect stroke-for-stroke copies of the Mona Lisa, would that make it not art? After a while, it's impact would diminish and nobody, IMHO, would consider it art any more.
It's like your favourite song, that you listened to just one too many times in a week, and can no longer stand. (EDIT: Or like yet another italian villa some person has built in the middle of joburg. Maybe the first one was a good idea, but after 100 it got a tad... repetitive)
I think there's something in this. I think true art requires novelty.