Yeah, at lower levels you will be able to kill Rogues while staying in Cat form and Warriors while staying in Bear form, or even Cat form.
You have to keep in my that player skills tend to get higher as the level gets higher. Remember the dreaded Barrens chat? Well, all those F-tards are in the 20-25-30 cause most of them aren't patient or skilled enough to get any further. (Which puzzles me cause the game is rather easy if you just try to understand the basic mechanics) So at lower levels you will often come across one of the 10 Alts of that Barrens F-tard and you will beat the living Hell outta him.
As you level up, it will become harder since players tend to be better and they get access to better skills just like Druids. You might still wander upon an easy opponent that won't force you to shift to win the fight from time to time but in general it gets somewhat harder.
In end-game, once everyone starts getting Raid gear, Druids have an increasingly hard time to compete. Well, at least, it was like that pre-BC and I dunno about post-BC yet. Other classes' gear used to scale much better than ours so we would need every bit of stat to stay in the competition.
We ARE weaker than all of our counterparts, it's no secret. But that is only true if we try to stay in a single form. Since we are like 4 weaker classes into one, we end being very powerful AND resourceful on how we deal with our foes and we should be able to overcome most challenges.