Why do you want auto-scaling gear anyway? None of the other companions have it.
Part of the leveling process is finding / buying / making improved gear for yourself and your preferred companion.
The thing is, you can unlock it at level 1 if you want, but it still comes with level 50 gear which is completely unusable. You don't have to provide any of your other companions with their initial set of gear. Even if the gear is not supposed to be scaling, HK should always come with a set of gear it can actually use. But scaling gear is the easiest way to address the issue of unlocking on an alt. Not everyone is going to get it at level 1, or 5, or 10.