Why vertical progression is poorly implemented

[Velhart]

I think part of why people don't follow a BiS formulae is because as soon as they get BiS it's replaced. so whats the point?

You honestly believe that people will follow a BiS formula for -certain situations-? The average player is not going to get multiple sets for one job to take on one specific task. Not even a lot of FFXI players did this. Again, it doesn't influence people to take on multiple jobs if they feel the need to constantly work on one job. Its a formula that doesn't work with this game and I don't recall people liking it in FFXI much either. Mages having to carry a HQ staff for each element, constantly switching between with macros. Its only needlessly complex. This game despite my complaints does accomplish making the system simple with a lot of depth. A horizontal system with multiple sets just makes it complex without much depth added, which makes it unappealing to the average customer.