Gunslinger need time buff and damage reduction like every subclass have when we use our super...8 sec is really less and most of gunslinger die when use super
If we bump the time then it everyone's going to turn to popping it really early and hunting people down with ease. And that's gonna cause more problems then there already is.
It's all about timing and accuracy.
Most Gunslingers die in their Super due to lack of player skill and awareness. It needs 0 buffs outside of PvE, and that's only accounting for 6-shooter. And maybe even fixing the exploit that allows it to 1-hit body other Supers in PvP, though it'd make the select few who choose to do so(especially if they've remade a character for it) very angry. But that was never intended in the first place.
This is coming from someone who mains Hunter.