Seeing this movie again for the first time in several years, I finally figured out the two strands of filmmaking that it's attempting (without really succeeding) to synthesize. It's a combination of the bold visual spectacle and brainy, existential concepts of 2001: A Space Odyssey, mixed with the turgid melodrama and flatness of an Airport movie. I mean, it even looks like an Airport movie (above) - if the future contains that much gray and beige, count me out.
That the movie works at all is a tribute to the no-nonsense craftsmanship of director Robert Wise, and especially to the talents of composer Jerry Goldsmith. His score really does most of the movie's heavy lifting to instill a spirit of mystery, romance, and suspense into what is otherwise a movie with a loooot of scenes of our actors' faces staring at very expensive visual effects.
This is also one of the few Star Trek movies to actually feature a high science-fiction concept at its heart - most of the really popular movies are adventure stories, first and foremost, but this one actually poses questions about man's place in the universe, artificial intelligence, and religion when it's revealed that the all-powerful force threatening Earth is actually a 1990s Earth space probe has been transformed into a super-intelligent artificial lifeform seeking to touch its creator. And it would be all a lot more interesting if it hadn't already been done a decade earlier in the original series episode "The Changeling".
The movie's narrative is rushed and sloppy - of the movie's three main characters, Kirk, Spock, and Decker, only Spock has a character arc that's actually coherent and fulfilled, and the 'Voyager 6' idea is anticlimactic - but I still have a fondness for this movie thanks to the basic spectacle and joy of the thing. It's not great filmmaking, but it's still a good example of the intellectual seriousness and grandeur that Trek aspired towards, even with flaws.