I feel they've kinda backed themselves into a corner with this. If they were to in a future expansion attempt to reduce the number of skills/abilities the immediate knee-jerk reaction from the fan base would probably kill the game.

I would like to also add that the problem isn't available hotbar space (some people always point out they have more space available) but rather ease of use for the player. The game in it's current form is incredibly cumbersome to play if you aren't using something like an MMO mouse or (sorta) a controller. Personally I'm not at all surprised so much of the player base has trouble playing their classes properly. I'd wager these people haven't gone out of their way to purchase extra tools to make the game playable and so they struggle.

inb4 DUMBING DOWN THE GAME RABBLE RABBLE RABBLE