The TMP set design has something the newer bridges don't have, which is
negative space. There's empty space between the stations and between different zones within each station. This gives the bridge a less cluttered feel to it in the sense that it looks like fewer personnel are required to be there looking at screens. The stations feel like highly specialized niches with a focal point for one person sitting down rather than a continuous series of flat-screen displays with random/repetitive information and no boundary other than the support-ribs.
This purposeful design is most evident in things like the extension that wrapped Spock's station.
Or the tactical station that is sort of nestled in a corner.
They're unique spots with a lot of visual interest.
Once the displays started to wrap around, yeah, it looked more modern, but also a bit too gaudy and information-overload. The wraparound effect first appeared, after all, in the Excelsior, and you were supposed to treat that as pompous and show-offy.
Another thing to factor in is lighting. While I liked the bright look of the bridge at the end of The Voyage Home, I don't think that overly lit white bridge would have looked good for an entire film, especially if the film had a particularly dark or somber plot to it.
