I was under the impression that "sensitivity" was determined by your ships Pitch/Roll/Yaw rates + Speed + Thrusters/Engineering.
They aren't complaining about sensitivity specifically. Its about the fact that fine aim is very difficult with controller sticks because their range of motion is so small. What they are actually complaining of is a lack of input curves to allow finer aiming, or the autoaim they are accustomed to controller sticks using.