Dunno about you but maras have more survivability than snipers by a large margin, far more disruptive on a single target, and higher damage. The burst in one gcd isn't as good, but we do ~1/3 more dps wtih a 6s interrupt, spammable slow, heal debuff and a charge (that also interrupts AND immobilises). If you think you have less survivability and dps than a merc you need to start playing with more than one hand.
Not to mention, how did we get nerfed? I really don't see why you ***** about it so much. Carnage never did damage in the first place (it got buffed and is still bad), rage got a major buff and annihilation was and still is far better than anything else. You need to learn to post, and learn to play.