well thats true to some extent, they had option set difficulty at LK dungeons.
But with all the addons etc it just went into easy mode.

WoW was a great game, but well...i hate comparing, its a diffrent game,
diffrent lore etc, WoW dont appeal much to me.

FFXIV, well...its new & still in progress so would be unfair to compare this to WoW or FFXI really.

There were FFXI windower, but wasnt as advanced as WoW's addons.
I think a customizable UI would do FFXIV good, maybe some addons too. (ofc they had to be accepted by SE first thou) Things like: Range Distance for ranged class etc, ingame calendar, show / hide menus.