I think you're missing the point, it is foolish, it doesn't map to reality, but that doesn't make it maladaptive. The point here is that the maladaptive group,

I think you're missing the point, it is foolish, it doesn't map to reality, but that doesn't make it maladaptive. The point here is that the maladaptive group, depressed people, see the world closer to its real state, clearly it is advantageous for humans to see the world through rose colored glasses to some degree.