Those are good points.

What I was trying to encourage was a practice of trusting your own strength. I think that morally conscientious people (as I suspect WrongBot is) err too much on the side of thinking they're cognitively fragile, worrying that they'll become something they despise. "The best lack all conviction, while the worst are full of passionate intensity."

Believing in yourself can be a self-fulfilling prophecy; believing in your own ability to resist becoming a racist might also be self-fulfilling. There's plenty of evidence for cognitive biases, but if we're too willing to paint humans as enslaved by them, we might actually decrease rationality on average! That's why I engaged in "prescriptive signaling." It's a pep talk. Sometimes it's better to try to do something than to contemplate excessively whether it's possible.