Or make some modifications to the complex, so that it could be self sustaining without an organic brain. The Enterprise computer handles that fine. But no, in normal western civilization, men and women live together, and Kirk was determined to force that on these folks, whatever the cost.
I'd say that that was probably not the only planet Kirk left in chaos, possibly mass extinction, due to his style of handling things...
It's classic era Trek, so of course the solution to everything is hetero-normative sex/marriage/partnership/free love

That actually makes me think... what did "Up the Long Ladder" have against artificial insemination? The Mariposans didn't like the idea of sex, the...uh...Irish Stereotypes (forgot their name) were big on monogamy (at least that's what was stated)
So wouldn't artificial insemination been the logical solution?