The fact that they have to see what will sell first and what won't. Really, it's basic marketing. Like there would be no reason for them to spend a ton of time and resources on cool new armors if it turned out nobody wanted armors from the Cartel Market.
You have no idea about marketing, basic or otherwise. People won't buy stuff they don't like. You're saying they are putting the junk armor in first to see if people will buy armor... then they'll spend time making stuff that actually looks good? Idiotic.
All they will find out is how many people will buy the junk armor because thats all there is. There's no way to tell how many will buy the "cool" new armors until.... wait for it... they add it to the market.