Isnt it the same principle in pve? Why should gear help carry you, why wouldnt it be more fair that at 55 every sorc has the same stats, and then if you have the most skills you are the best, its not dependent on gear.
PvE has hard numerical checks on its fights. If the stats on your DPS's gear are not above a certain level, then it doesn't matter how skilled they are, the boss will enrage and the entire group will fail. The most skilled healer on the server will fail to keep up with the damage in HM S&V if they're still wearing Columi gear. PvP has no such mechanic. In fact, mechanical checks in PvP are (in general) much more lenient, which is part of why wacky hybrid specs and strange rotations can be viable and indeed advantageous. PvE doesn't allow such margins. We can argue all day about skill in one vs skill in the other, but the fact remains that PvE has a very strong emphasis on numeric potential and precise execution. Numeric potential should be a non-issue in PvP since there is no mechanical enforcement of that potential.
And yes, the gear disparity is exactly as broad as I made it out to be. A 25-30% numerical disparity between players does not make for an even playing field. More importantly, I can be an incredibly skilled tank, but I would be absolutely facerolled by a mediocre player in better gear. That is the problem that bolster is intended to fix.