This feels like the root of transphobia against trans boys/men especially. The declaration is "You're a Female and a Girl/Woman, and I'm doing you a favor by telling you so," and that's used as the basis for interrupting the person's chosen language for their own gender/body, worrying who their friends and role models are, prohibiting how they'd like to dress, restricting or even criminalizing their hormones and body mods, body-shaming them, pressuring to establish where they can't publish or dictating what they can't perform, and denying all their narratives, interpretations, aspirations, and actualizations about their gender/body/sexuality, even when their gender is already the reality of their life. It's a kind of dehumanization that announces itself as salvation. Trans boys/men aren't fooled by that presentation for an instant. If people felt comfortable in their own self-perception, autonomy, creativity, and achievement, they wouldn't presume to tell someone else the right way to be a female or a woman.