Calling someone a "transphobe" is not strictly informational. What does that even mean? There are trans people who are against the trans self identity movement.

Calling someone a "transphobe" is not strictly informational. What does that even mean? There are trans people who are against the trans self identity movement. And there are trans people who think that gender != sex. On that note, why does the trans activist movement require that trans people must LITERALLY be the sex they self identify as? Why is that the one criteria?