That's only in the case of melee, casters scale a lot worse with weapons and for healers it doesn't even matter that much if they use a pvp weapon or not.
More specifically, it's a warrior problem due their insane scaling with gear and weapons. But hey, guess what, at higher ratings where people are equally geared, people get stomped by warriors as well.
Maybe it's just problem with warriors? Maybe it's just their class being very overpowered, with the gaps in low end and high end gear making it even worse? But for classes that don't have such a ridiculous scaling, gear is fine, deal with it.