Simplicity over complexity, time to change.

[Zantetsuken]

Horizontal progressions sounds nice but it's a utopia. Someone will do the math, will find the best combination, and anybody who won't follow will be ignored/left behind.

Have players discovered the mathematically best character in Ultra Street Fighter IV? Is there a mathematically superior color in any recent release of Magic the Gathering? Where are mathematically best choices in DOTA2 or League of Legends, or Pokemon, or weapons in CoD, or Diablo Builds, or Starcraft factions, etc. etc. etc. ?

Have you ever played Dark Souls or Monster Hunter? What is the best weapon is in either of those games? In a properly developed horizontal system, all choices have advantages and disadvantages that require players must weigh in finding what best fits their play-style.

Those games are great games because they have DEPTH. As players become more skilled in the game, they discover more subtle aspects of each build. The variety of choices they offer the players means that those players will be constantly experimenting and working to find style that works best for them.

ARR, on the other hand, has no real decisions to make and no depth -- Every job performs mathematically the same as every other job in it's role. Only the appearances and the order of their rotations is different. Gear has a single stat: iLvl. Everything in ARR is equal and equally dull. ARR is a place where players won't have to think about anything while they play (Apparently, thinking=stress for today's mass market MMO demographic). The design philosophy of 'accessibility and no-stress' ensures that ARR will be on the same track for years to come.

Horizontal progression is hardly a utopia. It has be demonstrated to work effectively in many, MANY games. But it is more difficult/expensive to create, and it requires players to invest a bit into the game in order to get more out of it.