Kirk also doesn't seem to grieve much when Ilia gets zapped by the probe. Decker does, of course, and doesn't like the cavalier way Kirk assigns Decker to work with the recreated Ilia-Probe as a sort of 'secret agent'. Kirk being somewhat empathetically challenged is very much a theme in TMP. I think they were going with him having a very selfish one-track mind to retake command of the Enterprise, so much so that it gave him a borderline personality disorder. When we get to Khan, Kirk behaves more like himself, but is just bored and brooding and not so much of a jerk.
That scene has always made me uncomfortable, particularly the way he says, "Carry out your assignment, Mr. Decker," as though there's no reason at all why Decker shouldn't be reluctant to interact with the Ilia-probe.
Later, after Spock was traumatized by his attempted mind-meld with V'Ger, Kirk stood at his bedside and demanded answers, even when it become apparent that Spock was too exhausted to even answer his questions. At the end of the scene, Kirk ordered that Spock be returned to duty, not taking McCoy or Chapel's feelings about his condition into consideration.
"I need Spock on the bridge."
Did he not think about Spock's fitness for duty? Did it occur to him that having a crew member working so soon after an injury could have placed the ship at risk? Spock had recovered, but there was no way to know that would happen when Kirk first discovered him floating back to the Enterprise