Lack of in-game occurrences and events (not talking about seasonal events). Let's face it, this game has no true reason to explore the world of Eorzea once you get a job to 50 and complete the ridiculously easy Main Story.

Why do I want to do the same FATES over and over and over again? Why do I want to do the same Leves over and over and over again? Why do I want to do the same instances over and over and over again? Why do I have to rely on a group to get things done? What is the point in gear grinding? What is gear grinding helping you do other than grind to get more gear? THIS if not resolved WILL greatly effect this game's long term future.

There are cannons in Coerthas. Make some real in-game events. 30 minute random raids where people have to defend. Instead of the place looking aesthetically pleasing like most places, this can actually be ruined and damaged over time and become a contested zone where you can't port to until the zone has been neutralized.