There are many factors to PvP balance.   I'd like to delineate some principles by which class balance should be contemplated.  I don't claim this list is exhaustive and I'm open to additional concepts being added.

1. Personal Experience is a flawed metric, but it's all you've got.  -  Keep in mind there are many factors that effect your experience, which in turn effects your perception of balance.
2. Some classes are situational in their strength/weakhness.  Eg. My WitchElf, depending on how the battle flows is difficult to play effectively in the T3 Crater Scenario due to the many choke points.
3. The Mix of Classes in a battle effects game play, classes fill Roles, a good mix of Roles makes DPS shine brighter because they have the support they need.
4. The Level's of the classes matter.
5. The skill of the players invovled matter.
6. The Gear of the players matter
7. The organization of small squads in the fight matter.
8. Character Builds matter.
9. Balance at low levels is HARDER to keep balanced, each level you gain from 1-11 makes up a huge % change to your skill sets. No one should be too concerened when they feel weak at level 6, there are worlds of change by level 8

Often as my WE, I can negate BW's nearly completely, but that's all situational, based on the scenario, and how well my team is breaking into their backfield.  Other times all my efforts are frustrated because I can't effectively get to the BWs and I'm burnt to the ground where I stand. We're not getting enough penetration for me to get into the back unseen.

WE's are highly situational, they are far too squishy to be universally effective. I accept that, I like the playstyle, I try not to komakazee, and play smart, strategic

Other classes are more like swiss army knives, good in any situation, like my brother's Chosen.

Yes its frustrating to be on the side that gets steamrolled, but that does not mean that things are imbalanced.

Keep in mind, there are roles in this game, Tank/ healer, melee, ranged.

I do believe every class fills those roles in a farily unique way, and each class is capable of fulfilling their roll. each class has a give and take.

Compare 2 melee dps.  WitchElf Maurader.

WE's have a higher burst DPS, but very little AOE, Mauraders get better armor and more AOE options.  Both have options for other utilities skills.  Each can build CC stun/snare, or just build in more DPS skills, or Anti healer or caster builds.

To a healer, the anti healer build seems overpowered, but the choice was made by the player to be less effectve vs tanks, and more effetive vs healers.  This brings me back to the original point, Personal Perspective is flawed, you can't know all the variables in play, you only know you got killed and you didn't like it.

So ask yourself about your class

Can I fill my ROLE?  If you claim no, I'm guessing you simply dont' want to accept playing your class in a way that it can be effective...consider another class, I've seen all the classes played effectively.

do I like the playstyle of the class?

Would I prefer a class that is more specialized or more universally effective?

Can I accept that there are situations when we're goign to get steamrolled and it has nothing to do with my class being underpower or the other classes being overpowered?

I am sorry but i have no sympathy here.

Witch Elves ARE universal. That is why some of the best destro 8 mans run 1-2 WEs in their tank train. Because the DPS and utility is amazing, and with a healer, they ARE NOT squishy.