So? You made up a story.

Here's mine: the island has a leader/owner, he takes the stone for himself. He tells the 18 incanters that they're obsolete, and lectures them about how the future is glorious and its all their fault they can't change with the times. Then he allocates more of the resources to himself. Sure, he doesn't "need" more, but it's abhorrent to pay moochers who are providing no value to him. He owes them nothing. The moochers die off, slowly or quickly, it doesn't really matter.