I would hazard a guess that a vast majority of WoW players have never even been to Azshara. Honestly, since Molten Core is no longer a major raid zone and the Runes of Fire Lords just put themselves out, there really isn't much reason to. Those of us who raided in vanilla made weekly trips there to pick up our Aqual Quintessence, and I was also an herbalist, so I would spend another hour or so out there looking for Dreamfoil because of needing a bag full of mana pots to raid in those pre-potion sickness days.
Clearly, the zone was unfinished. There was one quest hub, if you could call it that, because there were only a very small number of quests there. Blizzard tried to bring people to the unused zone later on by adding in the level 50 class quests that led up to Sunken Temple -- but really, in the process of leveling, you could basically ignore Azshara and move on.
I hated the original Azshara because it was out in the middle of nowhere and fairly poorly designed. It was hard to get to places because of all the rocky cliffs, and passages up and down from the beach to the cliffs were too few and far between. It could even be dangerous at level 60 before The Burning Crusade's stamina inflation; lots of mobs feared and or put debuffs on you, and there were elites wandering around over huge portions of the zone.
Sadly the few fond memories I have of old Azshara are gone, as well. When Azuregos was up in vanilla, the entire zone would become a raiding guild, PvP fight zone as the top Horde and Alliance raiding guilds fought over who could tag him, killing flagged members of the group who got him, hoping to wipe them and inflict them all with the debuff. It could get fun and entertaining -- and one time, it even caused our server to be shut down.
Well, that has all changed come Cataclysm.