It takes a full 50 minutes before we get Spock back and he loses that hockey hair. Arguably, we could have cut nearly an entire 30 minutes from the film at this point, hand-waving away key details. We could have skipped so many scenes and landed right at the point Spock helps to repair the ship and relays his impressions of a distant, space-borne consciousness.
In another film, I might have called much of the wormhole sequence and much of the set dressing to get the crew back together as a "filler". In many ways, it is. The development of the film's script was difficult not only for production reasons, but because this was the first attempt to translate Star Trek to the big screen. Growing pains are inevitable.
Moreover, the film is revealing it's true intent in all those loving model work and effect shots. This is less a film, and more a loving gift to fans of the original show. It's pretty, it's cerebral, and it actually does have a compelling (if slow) plot. There are reasons I recommend *against* The Motion Picture as a first introduction to Star Trek films; Wrath of Khan (or First Contact) is a far better choice.