One-time X-Men editor Louise Simonson has said the reason Chris Claremont’s X-Men run (starting with #94 of the Bronze Age run) included so many memorable women characters was that when he created a character he’d ask “why can’t this character be a woman?” And frequently there was no reason the character couldn’t be a woman, so she was.
That’s a neater trick than it sounds. For a lot of writers in that era (or even now), colorblind casting was not an option. The male protagonist or even supporting character was the default: characters are men automatically. Rather than “male or female?” it’s “male unless there’s a good reason to make them female” (trans or non-binary wasn’t usually in consideration at all). You didn’t need a reason to write a guy, but you did for a woman. Or a gay. Or a minority. And it had to be a plot reason, not just “let’s put a woman in this role.” That was just tokenism.
Max Allan Collins and Terry Beatty said in the letter column of their 1980s PI comic Ms. Tree that they’d include a gay character when it was significant to the plot, not before. Director Martin Scorsese, in a recent interview, said similarly that he wouldn’t write a female lead “if the story doesn’t call for it …. It’s a waste of everybody’s time. If the story calls for a female character lead, why not?” (Several of his movies have had female leads, as people in the comments noted). Lionel Shriver has similarly said deploying a transvestite or bi character might “distract from my central subject matter.”
As countless writers and readers have pointed out, the idea you need a story reason to cast a woman/gay/Latino/Muslim in the role has problems. As Foz Meadows puts it in response to Shriver, it implies that straightness/masculinity/whiteness is thematically neutral whereas gays/women can’t simply exist in fictional worlds: they have to be there because being there is the topic of the story or relevant to the plot: “By treating particular identities as “subject matter”instead of facets of personhood – by claiming that queer characters can “distract” from a central story, as though queerness is only ever a focus, and not a fact – you’re acting as though the actual living people with those identities have no value, presence or personhood beyond them.”
That doesn’t mean race/gender/orientation-flipping the characters always works: it’s possible to do a movie with a woman as the hardbitten sergeant leading her platoon to glory, but not if it’s WW II. Switching out the white guy for a black woman may make some of the story unworkable, or open up new options. Ms. Tree herself was as hardboiled a PI as they come, but I doubt if Collins and Beatty had written about a male PI they’d have focused as much as they did on the relationship with her stepson (the authors do a good job not making her a stereotypically nurturing person under her hard shell).
When I first wrote Southern Discomfort my protagonist was male. Gender-flipping didn’t actually change Maria as much as making her a nurse rather than a modern-day combat veteran (much less likely to fight). Raceflipping characters (not so much “why not a black character?” as “why are there no black characters in this?”) caused a lot of changes for the better, but as huge chunks of plot got cut out, I wound up dropping the characters and making a couple of minor black roles into major roles. That worked better.
So no, the answer to “why not a woman?” is not always “yeah, why not?” But often it can be.
#SFWApro. Cover art by Gil Kane, all rights to image remain with current holder.