The easier it is to level a class, the worse they will end up. Take hunters for example. Ignore all the crap about noobs being attracted to the cute pets or pretending to be Legolas. Overall I doubt the average hunter is significantly stupider than the other classes, or at least not enough to account for impressions of them. The problem is that hunters are absurdly easy to level and offer little challenge to the player, so they never learn. It isn't that the player is stupid, it's that he's uneducated.When leveling a rogue (at least soloing), you learn all the tricks of the class. You have to, or you will be spending all your time eating. Rogues are slow soloers. They might -in fact- be the hardest class to solo-level today.
back when I first leveled a rogue they where one of the easiest. Back then being able to do damage was enough to be an "lol-solo-class".
What im getting at, (when doing dailies on my hunter) is that players playing hunters are in fact *punished* for playing their class well. Or at least playing their class in the most damage-dealing way possible (which for pve purposes is what they should). If a hunter even tries to push his rotation anywhere other than autoshot with a sting and maybe a single steady shot, his pet will loose aggro and the mobs will turn to him.
I'm sure that some hunters will and can explain to me how you to use MD and fade and other nifty tricks in order to maximise your output w/o getting aggro.
But that really doesn't change the fact that soloing as a hunter is either very easy (and you won't learn adamned thing) or very very hard (for very little damage per minute gain).