Here's why:
* Gendered: "Frenchman" only refers to a male citizen of France.
* Inclusive language: In modern usage, it's more inclusive and respectful to use gender-neutral terms like "French citizen," "French national," or simply "French person."
Of course, there are contexts where "Frenchman" might be appropriate, such as in historical discussions or specific literary works. However, in general, it's best to use more inclusive language.