Shatner Snubbed: Why Iconic Captain Kirk Was Left Out of Star Trek Reboot
J.J. Abrams' Star Trek films were moderate commercial successes and well-received both by critics and by the general audience. However, they are fairly commonly criticized as "Star Trek films made for people who don't care about Star Trek".
A number of things served to alienate the franchise's hardcore fans (dwindling as their numbers were), from the very fact that the new films were a reboot, to William Shatner (OG Captain Kirk) not getting any sort of appearances in them, even though Leonard Nimoy (OG Spock) had significant cameos in both Star Trek 2009 and Star Trek Into Darkness.
The excuse used for both the reboot in itself, and for Nimoy's cameo appearances used the established rules of Star Trek universe, where travel backwards in time is possible, but every time it is attempted, alterations caused by the time traveler's presence and actions result in a new, completely separate and independent timeline branching off.
The timeline of the new movies is an example of this, created by the original Spock going back in time to eventually meet the new versions of Star Trek's protagonists, thus explaining Nimoy's cameo.
Initially, Abrams planned to add Shatner's cameo appearance as well, through a recording brought by the original Spock from the future. But according to Abrams himself, Shatner was not happy with a brief cameo appearance:
"We tried desperately to put him in the movie, but he was making it very clear that he wanted the movie to focus on him significantly, which, frankly, he deserves."
The problem, according to J.J. Abrams, was that canonically the original Kirk had died in Star Trek Generations, so incorporating his character for more than a brief cameo while preserving the logic of the story was difficult, and as Shatner did not want merely a brief cameo, the final decision was not to include him into the movie at all.
Which sounds reasonable, but some people still suspect that J.J. simply did not want to deal with the original Kirk overshadowing the new characters and pulling the audience's attention to himself.
Given Abrams' questionable treatment of legacy characters in The Force Awakens, minimizing presence of legacy characters in the Star Trek reboot was probably for the best.