World of Warcraft's classes, abilities, and content is continually evolving. This is to be expected because everything is subject to change over time; however, the problem is that the design philosophies that the game rests upon are not changing with the rest of the game. There is only one reason possible that design philosophies have not evolved with the rest of the game, and that reason is because the developers of World of Warcraft are simple too stubborn to admit that the old ideas that they are designing the game around are out of date.
An example is pvp. Pvp requires different ways of balancing, and frequently runs contrary to pve resulting in neither side being happy. Pve favors more complicated rotations so that skill may stand out when scoring dps charts. Pvp favors slower and more simplistic rotations because in pvp a player must pay much more attention to utility abilities. Thus if the two different aspects of game (pve and pvp) share the same rotations, then either only one side will be happy or neither side will be happy.
Another example of faulty design logic/philosophy is balancing pvp around 3v3. Balancing pvp around 3v3 is good for 3v3 only; furthermore, balancing pvp around 3v3 does not equate to good balance in 1v1, 2v2, 5v5, RBG's, and random BG's. The problem is that participants in 1v1, 2v2, 5v5, RBG's, and random BG's combined together far outweigh the participants in just 3v3 alone. This leads to a much larger portion of the player base being unhappy with class balance.
I have given two good examples of flawed design logic/philosophy. Now I will explain the ways in which to fix these philosophies/logics so that they better fit the modern gaming platform. In the first example it is clear pvp rotations need to be separated from pve rotations. This may be done be the adding of a forth spec to every class that is strictly for pvp only. This spec would have a different rotation that is designed to fit pvp requirements rather than pve requirements.
Next the view of balancing pvp strictly around 3v3 needs to change. Pvp must be balanced separately for each bracket. This means all spell effects must have different timers, damage, and diminishing returns for each bracket. There is no need to change every spell effect just how long the effect lasts, how much damage it does, and how many other abilities it shares diminishing returns with.
I realize these design logics/philosophies require a lot of work. However, there is a monumental difference of outcome when you take the time to do things right the first time rather than do them quickly.
I will not post a TLDR version; this thread is meant for players that are actually going to take the time to read closely and respond.