Tabula Rasa is that it is, in many respects, an incomplete game. The Specialist tree has undergone months of retooling and tweaking to be made truly viable, the disparate amount of content in the mid to late levels has been the cause for considerable concern, and it's fairly well known that the game lacks a significant endgame.
It's this latter point that has caused a crisis of sorts on the Pegasus server. Both Defiance and Tranquility, two of the larger endgame guilds on the server (or so we're told), have decided to call it quits because of the barren state of the end-game. All there is to do once you've hit the level gap is PvP. Problem is, the PvP in Tabula Rasa is pretty broken, and the development team hasn't shown much interest in fixing it in the near future. Or if they have, they haven't done a terribly good job of communicating that.