The Crafting character perks only improve your critical chance for augmentable gear. Every class can create at least one type of gear, so the perk still benefits everyone, but you shouldn't expect to get a bunch of spare hilts, barrels, and mods out of this perk.
I just corrected someone else in a thread on page two of the crafting forums... Bioware really needs to word this better, as they promised to do several months ago (admitting that yes, it was poorly worded).
Legacy of Crafting does increase the chance you crit and get doubles. See the official dev responses on page one and two of this thread: