The classes are so hard that I could be the highest dps in the dungeon and still feel like I am total ass because I know I'm not doing anything right.
You literally need like a week studying and practicing a single spec to actually get a handle on it. In many ways I think that's fantastic and is probably the biggest draw of the game.
That said, I wish there was a gradual process of learning as you play. There are too many variations with talents and builds to the point where you cannot even search up a rotation guide on the internet. You have understand every single aspect of your spec and create all these ultra complex priorities and have fast reaction speed. It feels so daunting.