^I disagree. Kirk was a very flawed, human character in TOS -- that was what made him interesting. He was often insecure and doubting himself, needing McCoy to give him pep talks (see "Balance of Terror"). He sometimes tended to default to overly aggressive or impulsive responses and needed Spock's advice to rein him in and guide him toward the right decision (see "Arena," "The Devil in the Dark," "The City on the Edge of Forever").
And he didn't have every woman he wanted, not always. He got nowhere with Eleen in "Friday's Child" -- true, he wasn't really trying to romance her, but she wouldn't even let him touch her, while she warmed up to McCoy. His attempt to seduce Kelinda in "By Any Other Name" didn't work as well as he'd hoped; rather than bowing to his influence, she became interested in exploring kissing for her own pleasure and was more interested in making out with Rojan than Kirk. And Miranda Jones in "Is There In Truth No Beauty?" shot him down in flames when he tried to seduce her. (It's worth noting that all three episodes were by female writers.)