I never ran into the level syncing mindset that others experienced. When I was in groups that used level sync, it was used more to work with what was available, or to keep a party going when some people started to out level the camp. The worst thing I remember with level sync was how badly gear scaled at the time.

As to adding it to FFXIV, I'm not sure if it needs it or not yet. As in FFXI there were spots where groups on the end of one camp would not really want you as you were too close to being overleveled for the spot, but you were still far enough away that the next camp would not work for you as would barely contribute. I don't know yet if there are spots like this in FFXIV, but those kind of spots are where it would be needed most.