Mainly the correlation between agility and maneuverability. A ship with 3 AGI, if being flown properly, shouldn't be getting shot at in excess (except turrets because turrets) and even against a turret, you have enough movement to stay out of range or go for the doughnut hole. This is a core ideal for a game such as X-wing.
The assumption here is that your Pilot skill is high enough to react. With this mentality, all the low PS arc didgers are out of luck...unless you have a few tricks, like Intelligence Agent.
Edited by Parakitor