One could argue he's revered by default. Picard has too big of a stick up his ass. Sisko is war criminal. Janeway is a murder. And Archer is a fucking bore.
I agree with Phoenix219 and Ragitsu. Two of my great great great grandparents were born in 1779 and 1801 and married in 1822 aged 43 and 21. They had 9 children, and I am descended from their son born in 1830. None of my close relatives would have been born without that marriage. I also note that KIrk and Karidian didn't have a normal relationship, since Kirk was using her to investigate her father, and she was getting close to Kirk to get a chance to murder him.
Honest Question not a "gotcha!": When did Gene Roddenberry disown the TMP Novelization? This is news to me. I know he later said he considered TNG to be the "real" Star Trek, but that's not quite the same as disowning the TMP Novelization, since TMP and Phase II are really just a rough draft of TNG.
Kirk and co. would have been booted out of Starfleet in Picard’s time. And we know how wild Picard was in his cadet days. Not really a wonder why Picard has a stick up his ass. Sisko would be more revered on Bajor. He’d be seen more as a General MacArthur or General Patton type in the Federation history texts. Janeway was the answer to what Kirk would be like in the 24th century. And Starfleet wasted no time giving her a desk job due to it and are hoping that she doesn’t get herself demoted to be captain again. Archer tortured a pirate before becoming one himself, was bigoted towards Vulcans and managed to get his ally’s government disbanded. Somehow, this made him Federation President material.
A bit harsh, but I agree Kirk was the most likeable. Archer's "bigotry" towards Vulcans added some depth to the story. The relationship between Vulcans and Humans not always being so rosey was more interesting than a "kumbaya" type atmosphere. Also, Picard and Riker demonstrated some prejudgments against Ferengi and Romulans at times. Rivalries happen.
I think "disown" is probably too melodramatic a word. It's just that, like most creators, Roddenberry saw his creation as a work in progress, was never fully satisfied with the imperfections and compromises in his earlier versions of the work, and was always trying to improve it as he went. So the way he saw the universe in 1987 had evolved from how he'd seen it in 1979, just as that had evolved from how he'd seen it in the 1960s. Also, he was a product of an era of television when strong continuity in a series was not expected or prioritized, because they didn't have home video and season box sets and wikis yet, so series were experienced more as a succession of independent standalone stories than as unified wholes. Look at almost any long-running series from that era and you'll see it playing fast and loose with its own past continuity, changing or disregarding previous events or referencing them only loosely with changes in detail.
I think it was around the same time he got all obsessive about what is or isn't canon, so around late 80s. IE, no novels are canon (and he did even specify "not even my TMP novelization") TAS isn't canon (which has since been lifted anyway) TFF is apocryphal (which has created a muddied situation regarding that movie ever since) and so on.
I disagree that Kirk had the easiest mission out of the various captains we see. I think in many ways he had a harder mission, as he wasn't as in touch with Starfleet and the Federation as most of his successors. The Kirk we see on TOS is left to his own devices much of the time. We also see Kirk come up with some of the most innovative solutions seen on any of the shows: The Corbomite Maneuver, destroying the computers on Eminiar VII that let them wage war with Vendikar remotely, building a makeshift cannon with gunpowder when fighting Gorn... TOS Kirk is basically a combination of King Solomon, and MacGyver. The fact that he's a ladies man on top of all that just adds to his legend. Honestly, I can't imagine that most of those missions would be known by the general public in the Star Trek Universe. At the very least, aspects of them would be highly classified. But Kirk obviously did something to become famous during the TOS era. Captain Harriman says in GEN that he read about Kirk's missions in grade school. And Kirk was a handsome, charismatic guy, younger than most of the other captains we saw on TOS, so it makes sense that the media would latch onto him. He's like JFK in that regard. But it's an interesting question: Which of the missions we saw on TOS would be publicly reported on? Certainly not "Metamorphosis" or "Mirror, Mirror." Even the diplomatic conference we saw the lead up to in "Journey to Babel" was classified. Anything that was reported about Coridan's admission to the Federation would be after the fact. Now, these missions I imagine would be publicly known. Earth was directly endangered in both TMP and TVH and Kirk saving the UFP President and exposing a huge conspiracy to sabotage the Klingon/Federation peace process happened at a huge public conference. That stuff is going to be reported on, and honestly, that's enough to make Kirk notable in history. TV Tropes has even named that trope: Famous, Famous, Fictional, with several examples from Star Trek in the "Live-Action TV" subsection. As someone who was raised by a loving mother and stepfather 13 years apart in age, a 15 year age difference has never seemed like that big of a deal to me. As long as everyone is above the age of consent, I don't have a big problem with it. Kirk/Lenore does violate the "half your age plus seven years" rule of thumb, though. (Assuming that Kirk is 33 during the first season, Lenore should be 23 and 1/2 years old for it to be appropriate by that metric. But hey, dating a younger woman ends up with Kirk exposing the true identity of Kodos the Executioner and catching a serial killer, so I'll cut him some slack there.)