It's accepted for parents to not be reasonable where it concerns their children. Unlike other instances of a person's judgement being impaired, it's not the norm to let another person be reasonable for them - or for them to seek out rational advice.

The outcome is that parents compromise their children's development because they're afraid their child will get struck by lightning under a blue sky. Chances are we're raising a generation of adults even worse than the last few: already many spend most of their conscious thought jumping at shadows, never grew out of relying on a parental figure, and have next to no agency. Luckily there's still enough fully formed adults around to shepherd them through life, but I do worry how bad the next bunch going is going to be.