I believe I have stated my opinion on this somewhere else here on the forums, so I'll probably repeat myself, but... I disagree. I welcome game series trying out new ways - incidentally, this is why I am seriously hyped for The Legend of Zelda: Breath of the Wild - but I also strongly believe that if you alterate your design too often, you fail to build up a strong identity. What the Final Fantasy series has been doing for a while now is the equivalent of chasing the white rabbit, but then stopping in front of the rabbit hole to go back and repeat the same procedure. There's nothing wrong with that, but this series has been doing this too publicly for a while now, and yet, if they do fix things, it can actually work in the games's favour - like XIII-2, where there was an option to swap leaders, a feature that has been strongly missing in XIII and made the overall experience better.
And, as far as I am concerned, I think FF is sometimes trying too hard to be special. The Crystarium was an awful idea in both of its iterations and I strongly question the merit of "discovering" this particular character progression system. These kinds of systems have been around since at least the birth of the tabletop/P&P RPG genre and I think any deviation from the standard "kill enemies, get EXP" formula should be done because it compliments the overall design of the game (like the Souls games, where Souls are more than just EXP, but also serve as currency (plus the way the whole mechanic with dying and being reborn works) or LabZero's Indivisible, which ditches EXP for items b/c of its Metroidvania DNA) or because the designers found a system that makes it actually interesting instead of being a novelty for novelty's sake, which is where I'd put the Crystarium (as well as the Sphere Board from X and the Draw/Junction System from VIII).