I do not think TK's should be wearing a pauldron.
That said...
I (IMO) believe there are only stormtroopers, one kind. They get issued different equipment as needed. The nature of the desert planets showed the need for an environment pack. Cold planets need different equipment.
I do not think the "Snowtroopers" are sitting around the ship collecting dust or getting drunk waiting for an "icy" planet to be attacked or garrisoned. the same for the TD's, unless during the battle for Hoth they were chillin' watching the battle on TV.
I think Lucas realized that the troopers running around on the deathstar would look silly wearing a pack ( and Pauldron) and would knock everyone over in the tight quarters.
As a kid I remember thinking the orange pauldron was being worn because the trooper was directing traffic, much like the cops where I lived.
Lastly, I think anyone who is a memeber of the 501st should post their opinion there, whether or not someone agrees with it. Just try to stay rational and not flame people