Yet Rodenberry introduced a female First Officer in the original pilot. And that was apparently shot down by the studio for the 2nd pilot.
It was NBC who objected, I believe. But per Solow & Justman's Inside Star Trek
, the network was fine with the idea of a female first officer; they just didn't like Roddenberry casting his mistress in the role. If he'd just recast, they would've welcomed the character, and she could've stood alongside other strong '60s heroines like Emma Peel, Cinnamon Carter, and Agent 99. But he couldn't admit that, so he blamed it on network sexism.
(I think Lee Meriwether could've made a good Number One.)
But I agree it seems that the intention of the script was to say that females aren't suited for such jobs especially Kirk's last line and Spock not disagreeing. I think we all wish at that point Spock had piped up listing names of females Starship Captains past and present.
I know GR was credited with the story but did he actually write the dialog.
He wrote the outline
solo, and it's pretty much the same as the final episode, with the addition of a really chauvinistic, even vaguely homophobic tag that was mercifully dropped.
Remember that GR also came up with the story for "Mudd's Women," which is just about tied with "Turnabout" for the title of most sexist TOS episode. It's hard to believe those didn't reflect his views to some extent.
I think that in his own way he valued women, but he accepted the assumption of the era that women's value was in different societal roles than the ones filled by men. Sort of a "separate but equal" mentality. He definitely placed a lot of importance on masculinity as distinct from femininity; that tag in the T:I outline conveys a definite dread of masculinity being undermined by feminine influence.