I'll be honest with you, it's not short and there are issues that have been there for a good while. The worst of these issues require programmer attention to fix. The problem with that is two-fold. 1) Anything that requires a programmer to fix takes time. 2) Programmer time is at a premium. We have a limited number of programmers available and their services are in high demand. Even with most of them putting in extra hours to try and meet demand, there's still a finite pool of time available. As such, it falls to the folks in charge to decide where that limited time is best spent. It then falls to folks like myself and Zero to remind the powers that be that these Foundry issues exist and try to get some of that limited time spent on them.
As I've said before, the wheel may turn slowly but it does turn, even if some of us have to get out and push.
So the quick answer is that not all costumes are available in the foundry. Without importing, the selection of costumes seems to be limited to what you would have for a base character with no special NPC costumes.
There are a few special ones in there, like the Insurrection-style dress uniform (the one you get for getting high diplomacy rank) and I believe the Enterprise, The Motion Picture, and Wrath of Khan uniforms.
But there are many, many that are missing. Something we've been elbowing them about for about 2 years now