No, it's not. It's total crap. Embraced by hipster-contrarians, but crap nonetheless.
It's exactly what it sounds like -- some kids who can't play the instruments given to them by their father who wanted them to be a band. Nothing more, nothing less.
The emperor has no clothes.
Ditto for this kind of "art".
Take, for instance, the canvas which Teri Horton claims is a Jackson Pollock.
If it's a Pollock, it's worth millions. If not, it's worth nothing.
That's just one example which shows that modern art is a scam, nothing more than a name game.
When you remove skill from the equation, all you're left with is a popularity contest. It's pure speculation.
Yay, Piggy's posting!
The Shaggs played their instruments badly in a unique way.
Worth hearing once, for a couple of songs.
What a crock of

.
And people paid to "hear" this, I suppose. The term "rich idiots" comes to mind.
The typical music-school-and-beyond attitude toward Cage:
Enjoyed those early prepared-piano pieces.
Hey, those late violin pieces--they actually sound like music!
Good writer. Brave advocate for...something.
Cage has a minor role--sometimes his example gives music students permission to try some new things.
==========================
Now that I think about it, it's precisely that market-value aspect of art that I'm trying to avoid. If my work succeeds for me, it's because it realizes some technical ideal well enough, and makes it sound good.
Artists, more fools than knaves, usually. More Don Quixote than Don Corleone.
To challenge myself, I'm trying to think of artists and musicians whose work makes me ask the question, "Do I want to try to imitate/absorb/appropriate anything here?"
These artists represent my "live" choices.
Not Cage or Pollack. Ok, then who?
For the limits of serialism, the extreme is represented by Stockhausen and Boulez.
For rhythmic complexity, Elliott Carter.
For tuning, someone like Partch.
For balance between older and new jazz style--lines vs. honking, say--Coltrane.
People like these define my search space.