Because just because it is a story based MMO doesn't excuse it from it being y'know AN MMORPG.

FFXIV is a story based MMO yes, but it also is a holy trinity MMO (as in it has dedicated Tank/Healer/Dps) and it has things that are MMO staples such as raids and dungeons.

While I will always say FFXIV has one of if not the best stories in the genre, it isn't going to save it from what I think it utterly fails at:
  • Lack luster dungeon content
  • Lack luster midcore content (that hopefully gets fixed with Criterion Dungeons)
  • Poor job design with Tanks/Healers in a Trinity MMO

And that's my opinion. I can give FFXIV what many people say is the greatest MMO (I don't agree) a complete 1/10 for job design if I so wish. Doesn't mean that it isn't a 7-10/10 for story.