Sure it has a real-world basis, just a terrestrial one, not a space one, which is why it is so stupid. The thing is like the old Moffet Field blimp hangar, looking very much like that shuttle departure area in the TREK trailer. Big waste of space unless you're berthing blimps on a planet.
Err, it's in space, so there's plenty of space to spare. Why
not enclose a large area? Gives the ships and workers more elbow room. The only thing being "wasted" would be hull material, but there are millions of asteroids you could harvest that from.
Of course, there's more waste if it's pressurized, but I don't think pressurization would be such a good idea, given that the ships are designed to work in vacuum. Also, if someone did attack the Spacedock, or if one of the ships within it suffered an accidental explosion, you'd want a vacuum inside so the shock and heat wouldn't propagate. If there were a large explosion inside a pressurized space habitat, the overpressure shock in the atmosphere could rupture the hull. (TV and movies condition us to think that fireballs are the dangerous parts of explosions, but what really makes them destructive is the atmospheric shock waves. In vacuum, that threat is absent, although you still have to worry about shrapnel and radiation.)
I'd WTC that sucker, crash it down into Earth.
Huh? Assuming it's in a natural orbit, rather than some kind of forced levitation, why would bombing it or crashing a ship into it cause it to de-orbit? Maybe if you crashed into its leading face on a trajectory directly opposing its orbital velocity, you'd slow it down a bit and cause it to fall into a lower or more elliptical orbit, but given the mass differential between it and a starship, you'd have to come in at a pretty high velocity to match its kinetic energy, and at that kind of speed you'd just blow it apart into a cloud of orbiting debris. Maybe a small percentage of that debris would be on deorbit trajectories, but those pieces would burn up in the atmosphere. If you wanted to crash the whole thing, you'd have to impart a sustained deceleration, tow it with a tractor beam to cancel its orbital velocity.
Yes, yes, I know, ST practically copyrighted the nonsensical idea of a spaceship's orbit "decaying" if its power was cut. But I rationalize that by assuming that starships normally maintain forced orbits, such as stationary orbits at low altitudes, in order to stay in comm/transporter range of their landing parties and such. In those cases, they would have to apply continuous power to avoid falling, since it's more of a high hover than an actual orbit. But there's no reason to assume that Spacedock would be in a forced orbit rather than a natural one.
Ok, it just seemed like you were saying that it wasn't transparent...and you can see through it. A tinted forcefield would probably solve the problem.
So would a door. I'm not a fan of the sci-fi tendency to embrace a less efficient, more power-intensive solution just for the sake of seeming "futuristic." It violates the engineer's maxim to keep it simple.
True, there is ST precedent for forcefields over hangar exits, but those designs invariably have physical doors as well. The fields allow a shirtsleeve environment in the hangar and avoid the need for lengthy depressurization and repressurization of the bay, but they aren't intended to take the place of physical doors and be in use 100 percent of the time. It's just common engineering sense to have a simple, physical backup system in case of power failures and malfunctions.
I think the large bay doors on Masao Okazaki's
Vanguard station design from the novels are a good design.