This explains pretty well and makes sense.
Oh, SWG was built on the Hero engine as well eh? This really is such an ignorant statement it made me facedesk.. you owe me a new keyboard.
Bioware already stated in the past that they made a bad judgement call concerning this and that the hoods are not a seperate part of the chest piece but an integral part. Making a toggle would basicly require them to either make a different, hood-down version of every hooded item in game and make a mechanism that switches these two chest pieces' look on command (with all inherent risks), or regenerate all items in game to ensure they have the hood as a seperate entity they can work with armor design wise and then make a hood toggle similar to helmet toggle.
So really, it is a lot more complex and there are no short cuts available because of a bad mistake very early in development when it came to determining what seperate parts made up a chest piece.
From this thread