I, too, have wondered about Roddenberry and Starfleet. I felt like TMP tried too hard to distance itself from TOS. That is, environment and uniforms are very sterile-looking for scientists and explorers.
Gene Roddenberry did not make TMP single-handedly. A lot of other people were involved in its creative decisions. Robert Wise was the director of the film and thus the person most responsible for its designs, final script, performances, cinematography, effects, editing, etc. Robert Wise also directed The Andromeda Strain
, which portrayed a similarly sterile, futuristic environment. It stands to reason that the look and feel of the TMP Starfleet was Wise's choice, not Roddenberry's.
And it wasn't about distancing from TOS. It was just about taking advantage of the ability to do Star Trek
with a far higher budget and more advanced technology than had been available in the 1960s. That gave them the freedom to redo everything from the ground up. Not to mention that the sets, costumes, props, etc. made for Phase II
were too lacking in detail to look good on a gigantic feature-film screen, and thus had to be redone.
Plus it was a decade later, styles had changed, and new people with new ideas were working on the designs, so naturally they came up with different designs. Not in order to reject or distance themselves from what came before, but just because their desire was to move the franchise forward and keep it modern and forward-looking rather than valuing nostalgia above all else.
Anyway, TMP's utilitarian uniforms made vastly more sense as everyday wear for scientists and crew than the Horatio Hornblower cosplay that passed for uniforms in TWOK onward. I could buy those heavy double-breasted jackets as formal dress uniforms, but they were absurd as everyday fatigues.
Then in the TNG bible and series, he stresses Starfleet is not a military but a scientific organization.
True. TMP is a poor example for the premise, but by the time of TNG, Roddenberry had evidently undergone a major change in his attitude toward the military. He was, of course, a WWII veteran himself, and his first TV series, The Lieutenant
, was set on a US Marine Corps base. TOS was overt in its portrayal of Starfleet as a military and Kirk as a soldier, though it was a military whose primary mission was exploration. But by TNG his views toward the military were rather different.
And he was definitely trying to distance TNG from TOS. I used to believe it was because he'd come to regret a number of things about TOS, compromises and mistakes he'd made or stories told by other creators that he didn't agree with, but I recently read (not sure where) that it was more for business reasons -- that since Paramount owned TOS at the time, he wanted to create something that he could claim as a separate, original work that he could retain ownership of. I don't know, maybe that was the only reason for trying to depict a non-military Starfleet -- in an attempt to be legally distinct from the way Starfleet was portrayed in TOS. (Although I'm not clear on how he thought he could do this as long as it was under the Star Trek
name. Maybe what we got is the compromise between what he was trying to achieve and what the studio and the other developers wanted.)