While I feel I've seen enough evidence to suggest that galleries are used to launder/manipulate the market, this writer's reasoning seems problematic. Her whole argument starts from a place of misunderstanding art entirely:

"You’d think the value of art would depend on its aesthetic value; a picture you enjoy looking at on your wall. How could a dismembered corpse artist be remotely successful? Yet these paintings were classified as desirable by the art market."

aesthetic value != "a picture you enjoy looking at on your wall"

and further, a corpse can't be enjoyable to look at?? (Picasso's Guernica, Caravaggio's Death of a Virgin...)

That'd be like saying the movie market is clearly manipulated because Blair Witch Project is the most successful indie of all time.