PvE is a gear game. PvP is a skill game. Gear progression is certainly important (and should mean something) in PvP, but it can't be the primary focus like it has been in the past. There are a number of really good reasons for this, but one of the most obvious ones is that there is no separation of warzones based on gear score. Part of this is due to lacking tech in the game, and part is due to comparatively low server pops, but the largest contributing factor is that warzones aren't designed to be stratified in the same way that PvE content is. Think of it this way: when you go into a PvE instance in your top-tier gear, do you randomly get assigned to fight Soa in Story Mode? Would you find it interesting if you did?
Of course not. It also probably isn't very fun for Soa, knowing that every time his instance is created, he might get matched against a raid group who out-gears him by 6 full tiers. Well, that's basically what PvP was all about pre-2.0. People are fond of trotting out that the gear separation in PvP wasn't that bad. Yeah, that's rubbish. I've seen the stats, and I know how things are calculated. The gear separation was immense. When I can queue into a warzone and end up fighting a player who has a 25-30% damage and mitigation bonus against me, that's not fun. For either of us. The player in top-tier gear probably got it PvPing because he enjoys PvP. Unless he's a very strange player, he probably doesn't queue into PvP exclusively to curb-stomp noobs: he likes the challenge and the ever-shifting tactics. I can't offer him a sufficient challenge because my gear cripples me, and he can't offer me an even playing field for the same reason.
Another really good reason that PvP can't be a gear game in the same way that PvE is comes from the way that PvP gear is obtained. I can sit at the off node and pick my nose for a few dozen hours and "earn" a full set of Conqueror gear. Yay, me! Say what you like about PvE focused players, but they do need to work harder to acquire their BiS. If you don't clear a boss in PvE, you don't get loot. It's as simple as that. Thus, PvE gear has a dramatically higher intrinsic value than PvP gear due to the time and effort invested in its acquisition. This implies a number of things in addition to the separation of PvP, chief among them that PvP gear *cannot* be viable in serious PvE since it is far too easy to obtain (and we saw the consequences of allowing this pre-1.2).
It's also worth noting that gear, in PvE, is how you unlock subsequent tiers of content. PvP is all a single tier, and so there is no content progression to match the gear progression. It would be like if the only content available in PvE were level 50 story mode flashpoints, which could be ground again and again to achieve BiS gear, by which the content becomes trivialized. That was the situation that we were in pre-2.0 with PvP, and it wasn't really fun for anyone except those who thrive on ganking the poor sods who were foolish enough to solo queue as a fresh 50.
Thus we have bolster in PvP. Bolster serves a couple of purposes. First, it levels the playing field at an entry level and for casual PvPers. Rather than having an unavoidably massive statistical disparity and handicap due to gear differences, we can have an extremely minor differential and a focus on skill. Players who are good at PvP but don't grind the gear can come in and be successful and contribute to their team. Players who are bad at PvP but who still have their full BiS (and yes, these people *absolutely* exist) will suddenly find themselves steamrolled in every match. That sounds like a good thing to me.
The second thing bolster does is it makes PvE gear viable in PvP. I know that's controversial, but it's absolutely fair. As I outlined, PvE gear is dramatically harder to obtain than PvP gear simply as a function of how loot drops work. If you're a bad PvEer, you don't get gear. It's as simple as that. People aren't going to be grinding BiS PvE gear as an "easy path" to success in PvP, since BiS PvE is harder to obtain. Thus, the people coming in with their PvE gear will simply be casual (but potentially quite skilled) PvPers who primarily PvE.
The thing is that bolster is a really fine line to walk. For obvious reasons, Partisan *should* be superior to bolstered BiS PvE gear (it isn't currently). It shouldn't be superior enough to completely bias the coin flip in an encounter, but there should be an advantage. Conqueror gear even more so. Bolster gives BioWare very fine-grained control over the exact disparity between bolstered gear and top end PvP gear, which is a very good thing, but it's going to take them a while to get the system precisely right and balanced.
I'm very confident that, given a bit of time, BioWare will find the right combination of weightings to make PvP gear relevant and the progression exist, without creating a significant (read: more than 5-10%) disparity between entry level and BiS. The point is to keep the skill factor foremost while still providing some marginal gear progression. Once that balance is struck, I think everyone will agree that the situation is superior to what we had before. Warzones will be more evenly matched and queues will pop faster since people no longer feel "locked out" of PvP content due to gear disparity. That sounds like a good thing to me.
(btw, I don't think any of these arguments apply to ranked warzones, and bolster in that environment is really silly)