Explanation for weaknesses with the ending

The film was well into production when Paramount announced that it was overbudget (probably due to location shooting at Yosemite and, later, Trona Pinnacles) and cuts were necessary. The most natural department to slash was the special effects; and since much of the F/X took place near the end of the movie, that’s where the cuts would logically occur.

Shatner’s original vision for the climax had Kirk, Spock and McCoy plummeting into a hellish pit while the beautiful ‘cherubim’ surrounding ‘God’ morphed into hideous flying gargoyle-like creatures that pursue Kirk, Spock & Bones into a fiery chasm. Since this idea was too costly Kirk changed the gargoyles into six hulking rockmen, but the rockmen were pricey and Shatner was informed that he could only have one. Thus a rockman was designed and test-filmed but deemed a colossal disappointment and the idea was scrapped altogether with the exception that the rockman can be seen for a few frames when the ‘God’ entity attacks Kirk (you can view the below-par test footage of the rockman on the special edition DVD).

It was then that Shatner realized that the movie in his head would be different from the picture actually filmed. Personally, although the ending sort of fizzles out and it’s obvious that something was left out, it’s also not that bad. Yes, Shatner’s original concept would’ve made for a more thrilling climax, but the conclusion is okay as filmed—not great or necessarily good, but serviceable. A few gargoyles or rockmen and more action would’ve made for some nice icing on the cake, but just because the icing’s missing doesn’t mean the cake is no good!