You wanna balance a game around a mode where AOE nukes own everything, more or less, along with very random factors such as siege weapons, the players(from scrubs following the commander icon to a well organised guild on ts) ect. I agree WvW is fun, but balancing around that would require Anet to give every class a huge amount of AOE ranged attacks, because those simply shine in WvW(putting aside camp assault and ox defending/assaulting).
And please, give anet the time to fix that rendering issue. Or else we gonna he have "balanced class" that suddenly gets total crap after the rendering bug gets fixed.
Come on now, by that response I can tell you really didn't play WvW much at all.
In WvW, it's important to have a good mix of builds. Glass cannon AOE builds can be useful behind a keep's wall or near chokepoints, but aren't really going to win a fight on the open field.
Check the WvW forums: turtling, inventive use of group stealth and mesmer portals together with strong organisation and planning ahead are winning WvW (as well as population, sadly and obviously).
As an example: last matchup we were assaulting a borderlands where we had absolutely no bases at all, we went for the enemy garrison anyway, which held their orb. We built siege golems at a safe location then ported them in to catch the enemy off-guard and quickly destroy their altar of power, which resets the orb, making it much easier to capture. All of this was planned ahead so we could take one of the bigger keeps later that day and carry the orb there once it had reset to its altar. Good luck finding that long-term planning in sPvP.
I might not care about sPvP too much, but I think it's only fair that the game attempts to be balanced for all of the different content areas. You might have lots of "scrubs" in WvW, but that's the case in sPvP as well, except they're filtered in tPvP. Anet has already made a great engine to support WvW imo, but the rendering issue still persists and is not the only problem I have with thiefs.
As for Elementalists, getting forced into a bunker / support build in which you are very effective at surviving and countering burst (though thiefs are still the ones that can take you out the quickest by far in my experience) but which is also extremely boring to play and which makes your damage drop down like a sack of shit, just to counter a number of lolspam specs that would kill me otherwise even if I effectively use 25+ buttons in a fight is not fine in my opinion.
The ele is a great profession to play when you catch people unaware or are facing people who don't play at their max or can coordinate with other classes. We have a great number of tools at our disposal. I too have won 3vs1 situations like you see in the little youtube montages. What those vids don't show you are the times when you've been absolutely blasted into oblivion out of stealth without any actions from your part changing anything, or the times when one thief has been abusing stealth spam to keep a whole team from capturing a point (there's plenty of footage of that). And no, I don't think that's fine.
For the record, I don't run a pure DPS build most of the time, I'm actually full support / bunker right now.