These are just choices

Katt Monroe's design in the new Star Fox is the best design she's ever had, specifically because she looks all f'd up.

Here's the exercise: put aside everything you already know about what she looks like, and imagine that we, in 1997, are given the original description of who Katt is, what her history is like, and that we are trying to create her design from first principles. Blank slate.

Here's what we know about Katt: she's a mercenary and a lone mercenary at that. No Great Fox starbase, just her and her fighter freelancing in the galaxy. She's a former criminal, who used to run with the Free-as-a-bird gang back in the day, along with Falco, that's how they know each other.

Well, criminal, space mercenary, that to me says "rough around the edges," that's someone who gets into fights and drinks in seedy space bars. And if she's a lone freelancer practically living out of her ship, well, that probably gets kinda messy. I dunno what sanitation is like in a light fighter craft, but I don't think the Arwings have shower units installed by the engine. It sounds like a character who maybe does her showering in space motels or whatever the galactic equivalent of a truck stop restroom is.

With only that information in mind, what kind of character design do you imagine? What kind of person fits that description? Well... I think it's a person like this: a f--ed up scrungly alley cat, who looks like she says "hello" by punching you in arm, sleeps in her makeup and maybe dyed her fur pink once upon a time but it's long since been washed out, or bleached by unfiltered UV space radiation. Someone who doesn't look like she takes super great care of herself, and who runs on energy drinks and gas station drugs between jobs where she's either bringing in bounties or killing people. Someone who it makes sense to encounter on a planet like Zoness, which is one giant industrial toxic waste dump.

In the original Star Fox 64, Katt is literally the only female character in the game, and her entire character design, in common 90s style, is just "girl." She is The Girl One. She's the one that's pink and wears makeup and has an earring. Her character design has one note and that note is "feminine," whereas her status as a mercenary, a freelancer, a space gang member, all of that is buried under just mountains of "she's the girl one!"