From Developer Q/A:
Murshawursha: What was the logic behind choosing which Crew Skills get to craft Augment Kits? In Game Update 1.2 and before, if a player wanted, for example, an augmented Lightsaber, they HAD to buy it from an Artifice. Post-Game Update 1.3, if a player wants an augmented Lightsaber, they choose a Lightsaber that they already own (probably acquired through raiding or questing), and buy an Augment Kit from an Armstech, Armormech, or Synthweaver. This effectively cuts out the Artificer completely out of the market for augmented Lightsabers. Why was it done this way, rather than simply allowing Artificers to make Augment Kits that could only be applied to Lightsabers or Relics, Synthweavers to make Augment Kits that can only be used on force armor, Cybertech on earpieces, etc?
David: There are two primary reasons that Augment Kits are limited to Armstech, Armormech and Synthweaving: 1) They are the augment crafters, and Augment Kits extend that service. 2) Prior to crafted augments, they did not have a substantial input into the item mod game and we want to open that up to more players.
We did not want to have lots different Augment Kits, because that would make finding the right item and kit combination substantially more difficult. Augment tables are intended to make it relatively simple to get any item to the same power cap, and lots of kit variation introduces the possibility that it would be hard to get some items to hit the same potential. While this is how augment tables work now, all Crew Skills will continue to evolve based on player feedback and game data.