It would be useful to highlight the rewards of being rational to parents and I suspect it wouldn't matter much that the messages aren't "comfortable" as long as they can see a payoff in smarter / wiser / less gullible / more successful children.

If rationality isn't useful as a tool to build a better life there wouldn't much practical use in it. I would think parents would be hungry for a message that gives their kids (and themselves) a better chance in the world.