JC was introduced with BC. They dropped most non engineering character power items, all for the same reason. They tend to be required in raids and add farmtime. Of course, some like the LW drums are still functional and now widely used in challenge modes, but the JC ones simply outscaled. I agree though, I would like to have some updated ones. They used to be useful.
But really, they removed all the cool "fringe" items when they balanced professions to keep people from complaining (like that will ever happen) Giving JCers a bit of extra healing, or giving BS's a bit of extra damage from the Sharpening stones, was scrapped.