I'm about actor, not personage.
Personage had women (and, at least, one child), but did not marry them. Maybe in that future marriage was lesser common than today. In Russian sci-fi of 1960s it seems to be such at Efremov and Strugatsky ("noon" series). As Star Trek future has no money, they have kind of communism, so probably relation to marriages has the similarity too.but rather because he never met a woman he liked better than himself
kirk's every emotional need is met by spock or mccoy? the relationship with spock is kind of like a romantic friendship. i think kirk's an EIE and a workaholic, and yes, married to his ship. he does talk about the enterprise as though it's his ball and chain, but i think it really is just a symbol for his relentless need to be out in space on these life or death adventures. it's kind of a form of thrill-seeking on some level. and he's always been torn between that and having a family or something, and it hurts on some level, but isn't nearly as important to him as his work (work = flying by the seat of his pants, solving problems on the fly and giving impassioned speeches about morality... oh and often saving people). his relationships with women are usually dalliances.
unless you mean the new movies, in which case i agree w SLE. that kirk seems to have all these awkward Fi PoLR moments, as i saw it.
i think shatner is SLE.