The reason I stopped playing is because I feel like I had nothing to work towards. When you can put on any gear in the game as soon as you find / buy it, what's the point?

My favorite thing about FFXI is that it had an enormous amount of challenging low-level content.
A multitude of NM's within even the first 20 levels, some with great rewards.
Interesting and challenging missions, shoot, even only as high as level 25 I think, mission 2-3 was epic as hell.
A VARIETY of quests, which, while most had worthless rewards, almost all had interesting stories.
Working towards that next piece, or set of gear.
Vastly different areas to explore.
Collecting maps, I was personally a map whore in XI, I had almost every one when I quit.

That said, I quit because the game felt pointless. Grind to cap, then do what exactly? FFXI had the best "journey" experience of any game I've ever played and that's what I wanted with XIV.