Bottom line some players like to feel secure that their one tricky pony is ubersauce many others enjoy games that challenge them to learn their class, their abilities and limitations.. balance keeps that process from drying up imo.
Sorry but while I can't speak for the Sage/Sith as both mine are low level, the Trooper and especially the Gunnery is far from being that ubersauce you are mentioning.
I dare saying mostly everyone agrees on the fact it needed beef not nerfing.
Playing a Gunnery trooper was kind of masochist before now it simply sucks in PvP.
Before leaving, to the players complaining the 360 sage Knockback was of an issue in PvE, the issues does not lies with the skill but the player at the other end. A half decent player can position his character to push the mobs in the right direction. Thing is, with the 360 one they also had the ability to clear the area around them and especially behind, which they can't anymore.
Again in PvP everyone knew they had this skill, as much as everyone knew Troopers had KB. You know what: we adapted and it was part of the game. The only issue we all had is there was too much stun locks in TOR.
Point being there is even more Stuns lock in TOR since 1.4 and classes that needed a buff have been nerfed.
If at least they would have handed us a free AC to AC respec.