The problem:
A: Rogues starting with daggers, and daggers being called the most iconic rogue weapon.
B: Sinister strike being the first attack a rogue gets, which they are taught to spam. And being further encouraged to spec combat for levelling.
They just don't go well together! Like, at all. Rogues should either start with a slow sword in the mainhand for proper Sinister Strikes, or given a new level 1 abilty that benefits from daggers more. All these rogues doing awful dps spamming sinister strike with some lame as 1.40 speed dagger in the mainhand exist because they aren't taught any better.
And you, who bought 2x boa daggers and levelled as combat, maybe you did do fine, but you could have done MUCH better if you got the 2.60 speed boa mace. If you want to use daggers be Sub and use ambush to 1-shot mobs and go muti at 50.
I hope in Cata they fix low level rogues so there won't be so many awful ones. Cheers.
Edit: I'm not saying rogues are hard to level, I'm just sick of seeing other rogues (even level 80 ones) who are still using SS with daggers. I'm saying rogues are taught wrong and most of the players suck!