The usual inability to believe that a female or child could really have a strong feeling of distress or a problem with accepting males into their spaces
Some people do not see girls (or women) as human beings, with human feelings, agency or the ability to speak for themselves. We're a kind of template to them, with certain hairstyles, empty, smily faces, a collection of simpering giggles and no actual thoughts of our own. Perhaps this is why there is so much rage when women/girls actually do speak - must be like having a dolly that suddenly starts refusing to play along.