Not one negative word was said when your daughter wanted to dress as a boy.
I think you’ve hit on two simple but profound concepts in this piece, which by the way is lovely and a delight to read.
First, people need to stop being mean to one another. We’re supposed to learn that in kindergarten.
Second, people don’t like boys dressing as girls because deep down inside they think girls are worth less than boys.
I’ve written about the same thing through the lens of my own adult experiences doing Halloween in drag: