Not ever helpful? You would be mistaken, however, let me put it this way. You want lock on mode, to continue what it does, and let you properly strafe around a target, but IF you press anything that's not left, right or forward, you want it to immediately flip you around and run away. You want only ONE direction to be legacy while locked on, but to keep the rest the same. Lock on is designed to keep you FACING the target which is how it makes it so you can easily strafe on a controller. Which is why I said it is intended to compensate for the shortcomings of controller/legacy movement. If you don't want to backpedal, you unlock.