I've played my rogue since vanilla. We just are not as flashy as the other classes. A lot of my old rogue friends are either DKs or something hybrid. Rogues outside of pvp can be boring.
I leveled my rogue 1st to 85, then my DK. The DK was op as hell compared to the rogue. Both done with no BoA since this was when cata came out. Soloing mobs with even 300k hp was a challenge, the DK on the other hand just rips through like it wasn't even there. Plus death strike...I don't need to elaborate there.
I can see why a lot go with DK if your not big in pvp or could care less.