I absolutely despise talent tress for the following reason:
1) You need to look up the randomly designed singular motherfucking path and progress along in order to be able to unlock the one ability you like.
2) It's cluttered as fuck: too many choices and you always feel like fuck I'm missing one of my most important abilities now!
3) It's a nightmare to balance! 38 specs and 13 class trees on top of it: Just how the absolute fuck does Blizzard expect to keep them balanced?
4) Players literally forced to always change talent points now. On a per pull basis. Imagine the time it takes to re-talent every single fucking button you have in raids.
5) Imagine the time and resources this clusterfuck takes away which could be spent on other areas of the game. Every time I open up WoWHead I'm bombarded with a FULL PAGE of class and spec talent changes now. Who the fuck even cares? Just give us the tools to play our class and spec and be done with it.
And the list goes on and on.
I was so happy when MoP finally removed this talent tree bullshit. Why bring it back now?