I think within the context of the themes of TMP that a cold and distant Kirk makes sense, but it was just unsatisfying for Trek fans to endure.
The scene in sickbay helps validate Kirk acting the way he did, as it was somewhat of a role-reversal. Spock arrives on the Enterprise and brushes aside the pleasantries, but in sickbay it's Spock who reaches for Kirk's hand and tells him that V'Ger does not understand the concept of love (in any form, platonic or otherwise), and Spock does, whether he chooses to embrace it or not. There's a lesson for Kirk to learn too.
That scene is remarkable because Spock openly laughs. He shows more positive emotion in that scene than Kirk does in the whole movie. This was clearly intentional.
So I think by the end, not only Spock has become a softer character, but Kirk too, symbolized by the way he winks at the end.
It's just that presenting Spock as cold and distant is in-keeping with audience expectations. Presenting Kirk as cold towards his veteran crew is not, and it's not very satisfying to see him act this way after a 10 year gap of Trek. It's maybe okay for modern audiences to see him act this way, knowing that he softens later, but that's a whole different phenomenon.
In Trek II, Kirk is suffering from the same problem he did in TMP, the lack of the Enterprise. But instead of being obnoxious to everyone around him, Kirk keeps it inward, having quiet heart-to-hearts with Bones about being over-the-hill. This approach was more satisfying. The playful side of Kirk is best typified when he gives his inspection of the Enterprise, and cuts it short with the silently lipsynced word "Later..." Kirk is disturbed by Saavik taking the Enterprise out, but does not rush forward and pull rank in order to stop it. He's just not so damn uptight and micromanagerial the way he was in TMP.
The character of Kirk evolved further by the time you get to Search for Spock. Remember the dialogue Kirk gives to the crew right before they depart? He prefaces it with "My friends..." Search for Spock is the complete opposite of TMP. It is the renunciation of ego. It's all about sacrifice for friendship, up to and including the Enterprise itself, the object of desire that Kirk fought so hard to reclaim.
If TMP had been the only Trek film, it would have been disappointing. Only within the context of them all can you rationalize it as being part of larger character arcs.
The stewards of the Trek franchise at the time, Gene and company, for whatever reason, chose not to venerate Kirk's iconic heroism in TMP, but rather chose to present him as a much more flawed and unsympathetic character than any of us would prefer to see. No matter which edit you want to watch, that flawed vision of Kirk is going to be there.