Thanks for posting this, as you can see the biggest drop was due to the lack of direction, which a lot of MMO players at the time were not used to, since they have been conditioned by WoW and those kind of games. I am not criticizing this, I am criticizing the prolonged period of having so few skills to use compared to the previous version of skill unlocks.
If I was criticizing that, I would've complained about the game director on the UI, which I already turn off since its optional.