The purpose of FFXIV: A Realm Reborn is that it is a big overhaul to the massive failure that was FFXIV. While FFXIV was successful in concept, it lacked in practice. The fact that it was a P2P game with a fatigue system combined with the long generic map system had devastated the game. After this failure, the game went F2P while they began to rework the game completely. It took them over a year, but when they succeeded, they announced the game back as FFXIV: A Realm Reborn.
The main problem with FFXIV is that it took too long for this overhaul of the game to happen. When it was performing poorly in the beta tests, they largely disregarded the comments of the players and assumed that the masses would like what they had to offer. Instead, they had the opposite response with people largely disappointed and subscriptions dropping. Two years for an MMO is a very long period of time when many games often hit their make or break mark by six months after the initial release. The fact that this gigantic overhaul took place means that they probably spent a lot more money on the game in order to try to make it succeed. From what I hear, they are still trying to push it to be a P2P game despite all of the failures that it has gone through. It would probably take them much more if they are going to adapt the game for a F2P market under its current designs. There is definitely room to improve, but I feel that it is too late and waiting halfway through an MMO's life to fix the major flaws of the game is a big mistake.
Another problem is that the game barely makes any use of the trademark Final Fantasy themes. The only element it seems to largely keep intact is the music. They took their time to implement some of the names of classes as part of advance classes, but the overall feel of a Final Fantasy game is largely empty. As a result, it feels more like it is only a Final Fantasy game in name and seems to be more like a generic fantasy MMO. We never really see or hear of a larger villain other than in the history of the online Final Fantasy games. Had the villain been an active participant like orchestrating the formation of strong enemies, it could have been a lot more interesting overall. Considering that the story is usually a major part of the Final Fantasy series, it does not make sense that the online entries should not be any different. Your character seems to fight because that is what they know, rather than discovering why they are in the fight. Many people have not gotten over this fact and feel like the game should have been named something else entirely to dissociate it from the Final Fantasy name. It took them a long time to even put back some of the common themes of a Final Fantasy game.