I hear what you're saying, but I wouldn't put too much stock in that observation. By that logic, the entire Universe must have an atmosphere, since we can hear (and see) Phasers firing from starships. I think the only reason we see those spotlights is they help give the miniatures a sense of scale. I know you're a smart guy & have probably put more thought into this than the art directors at the time, but I wouldn't read too much into "artistic license."
If you want to get nitpicky about TSFS, how come when Kirk & crew sneak aboard the Enterprise, the first thing they do is turn on the spotlight on the ship's registry? (I know, it's dramatic & it looks like someone is flicking on the lights to the bridge, but still...)
I agree 100% Kirkunit. Not once did I ever conjecture that there is an atmosphere inside the Starbase, nor are we ever led to believe there is one. People aren't flying around in convirtibles, they are in shuttle craft of various design. And in TNG we see a sealed gangway or whatever it's called leading to the D.
Okay, then... can you give a reasonable explanation for why they'd be "pulling inside" of a big enclosed space with a heavy-duty door system?
Any logical argument whatsoever? I mean, besides the "it looked cool on-screen" argument... which may be true but is utterly pointless, unless you assume that Starfleet designs things not so that they do the job they're supposed to do but instead so that they're "kewl looking."
Honestly, I can't imagine ANY reason to have a big enclosed environment like that... unless it's different than the environment OUTSIDE would be.
If you only need privacy... why the heavy doors and so forth? Why not just put a thin panel "shade" around your docks?
I'd love to hear any reasonable alternative reasons.