Left for dead . . .

Went out to Sandy Beach this afternoon, hoping to get some sunshine, but left it a little too late.  Wandered the beach stretch anyway, then as a mother and child moved away, I wandered across the rocks towards an inlet.  Found this rather gruesome discovery spread out on the rocks.
Now, I eat fish, but why didn't the fisherman throw the carcass back into the ocean, rather than leaving it to decompose on the rocks?  And why did they leave behind the best part of the fish (the fish cheeks)?  A puzzle . . .