Yes. We'll see how well the game does in that regard over the long run.
It totally makes sense how things are falling out, though. The four classes with the most unusual systems are the least favorites. Either ANet is having trouble making them work (and be balanced) because they are unusual, or players are having trouble figuring out how to play them for the same reason, depending on who you talk to. My guess is it's a little bit of both columns.
I'll admit, the ones I'm attracted to most aesthetically are Mesmer, Engineer, and Thief, but I'm not the best video game player in the world, and have concerns about being able to learn those trickier classes well enough to keep up with the Warriors, Rangers and Elementalists. I like the aesthetics of the Guardian as well, and it seems to be in a pretty good place design-wise, hence the reason it's at the top of my list.
I couldn't get my head around Engineer at all when I played it. Just felt clunky to me the whole time. I really like the idea of Mesmer, but there seems to be an intense amount of snap decisions that are crucial to playing it right whereas other professions feel like they have a bit more wiggle room. I love the idea of shadow stepping all over the place as thief, but as a noob do I really want to play one of the squishiest classes in the game who is reliant on quick reflexes?
At least in the first dozen levels, playing Warrior or Ele was like night and day with the other classes. I'd play something else for a while, then get on Warrior or Ele and walk around facerolling through the countryside.
The other thing is versatility. Warriors, Eles, and Guardians have such clear desirability in all aspects of play. You're going to want them in dungeons, on sPvP teams, and in WvW. The other classes are a little more difficult. What is the thief's role in a big boss fight in a dungeon? Other than a few gimmicks like reflecting ranged damage and creating teleport circles, how will a Mesmer fare in WvW with illusions getting nuked as fast as they can bring them out?
I expect there will be a way for every class to work in each area of the game, but it'll take a little more thinking to it them into a team than it will for Warrior/Guardian/Elementalist.