Why? That's not very hard to do.
Things which "not very hard to do" are usually boring because of lack of complexity.
Starship's cockpit sound is very complex or suppose to be very complex: engines, transmissions, radio-transmissions, computers, system sounds, AI... - all the sounds what randomly change/appear/disappear through time and make you feel like you're inside of working dynamic mechanical system, not in ventilation pipe
It is also important because of player have no real cockpit and need some sort of "sound illusion" to make game/sim believable.
Of course, these sounds can be recorded mechanically (using fans and vents as well) or synthesized. In case of recording sounds from mechanical things there will be some difficulties - microphone quality, isolation from other sounds, isolation from reverberation... it means to take a good, high quality sound of any objects you'll need studio environment/equipment/recording engineer.
I wouldn't recommend to any game/sim developer to try to imitate sounds of real world/objects, because these sounds are connected to things, creating them (like real starship cockpit) and without visual representation of objects can be just boring. Thus, if you have a real cockpit - you may have a simple sound; if you have only sound and no cockpit - sound should be complex to compensate the absent of real object.
The best way could be combination of both parts - sound which is "real" and "interesting" at the same time.