There are some great stories in this thread.
I agree with the OP but in no relation to the PLing. The progression is not there, nor was it ever. I certainly hope it returns with the map redesign and it sounds most likely that it will based on what Yoshida has said regarding it. I think with independent areas there will be significant mob re-locations involved and that that will break it up a little.
I too have the same fond memories as many do with their first step into Vana'diel, making friends, joining their first LS and everything else that came. But, XI was my first step into the MMO world and most of the nostalgia and feeling I have for the game comes from that fact. I do have some fond memories from Aion in the beginning but again, that was a first (PvP) that inspires the sense of fun and adventure.
Although many of us have fond memories of our first exposure to those zones and experiences most of us dreaded going back to them on our 2nd, 3rd, 20th job. I don't ever remember hearing "Yay time for Valkurm again!" outside of a sarcastic comment. The same goes for nearly every other zone, much to the point where people took to soloing and powerleveling in XI to avoid them. My point being, most of the players now having at least 1 lvl 50 have no desire for a grind like that.
The main problem is that there is no awe inspiring sense of progression at all so nobody cares to enjoy what doesn't exist. There are no milestones yet, the Job system strives to change this but will it? Should that change in the future and people start enjoying the grind a bit more then powerleveling will likely go down.
For the longest time I have stood by and been a supporter of the game and franchise. But, without a massive, massive overhaul to the story and progression I fear even 2.0 will fail.
Yoshida and the Dev team know that that sense of progress doesn't exist so if they don't fix it their heads will roll as it is a franchise staple.