Earlier quoted context omitted.
While it's sexist, it's also a form of bullying. Bullying is generally punished in schools. Sexist remarks are also punished in the workplace. It is not "preparing kids for the real world" so much as it is "failing to respond to a situation in which a child is bullied."
> Bullying is generally punished in schools. Missing citation.
I can't really speak to efficacy, but a formal accusation of bullying is a big deal these days.