Because i despise that term? I hate that everyone missuse it as a generic term to describe any guy remotely feminine looking? Even thought a femboy is literally JUST a boy that look feminine? That means short hair and boy clothes. In some subcases, thicc. And a decent part of the actual people that call themselves as such, are attention wh###s, clingy and toxic when not given attention?
So i don't want to be given that term in any circumstances.
To further the first point. A crossdresser is not a femboy. A crossdresser is someone that enjoy dressing up as the opposite gender. It may sometimes involve wearing wigs or growing their hair out, and even using make up to look the part.
A trap is someone that look naturally as the oposite gender or could pass as both, leading to confusion. Etc etc.