Well I want to keep this post a bit shorter so I'll just say this. If you aren't opposed to suggesting SE rework the entire core of the game as far as jumping and navigating terrain are concerned, then I have no counter argument. My only comment on it is if jumping really warrants so much time and effort being put into sweeping changes. In my mind no, it doesn't seem a critical enough gameplay element for something like that. When you think of mmos you think of leveling, fighting, partying, running dungeons, etc. Those are worth the time, jumping not so much.
You also have to keep in mind mmos are consistent worlds. It's not like a single player game where you'll encounter hidden paths and secret areas a few times. Once they're discovered, once the patterns are understood, they no longer hold that luster they once had. Jumping would be the same way as far as hunting treasure and stuff is concerned, it becomes a needless obstacle. It'd be no different, ultimately, than putting a door in the way. I mean the secret beach in Valkurm, after a short time, wasn't really secret anymore. After that initial "Oh wow, a hidden path!" moment, it was just another area. Monsters scouring the hallways, the chance of mimics, things like that are dangerous aspects that always play a part. They're unpredictable and dealing with them can always maintain some element of fun.
The extreme response to what I said might be "Well they should just take away all obstacles if that's how you feel!" which isn't what I'm getting at at all. I'm just saying the level to which the game would grow because of jumping isn't as great as some would believe. Without some critical gameplay changes it'd be nothing more than a tacked on experience.
I suppose we could take Blade and Soul as an example. It's not out yet (that I know of) but we can probably analyze it a bit. Jumping was well integrated into the game. It's not only a way to explore but a way to play. It's used to navigate dungeons which were specifically designed for jumping, and they, if I recall correctly, created a whole mode where you can jump and run along walls and such. XIV isn't a game like that, it's just wasn't built to be that kind of experience.