It wasn't a matter of wanting it. It was a matter of needing it. The difference between FFXI boss fights and WoW boss fights was that FFXI's were mostly time sink tank-n-spanks with some very minor actual battle mechanics that made fights dynamic. WoW's boss fights were extremely fast-paced, with 10-15 minute limits before the boss automatically kills everyone. These bosses also spammed multiple AOE CC abilities, AOE damage abilities, shields, and also had such mechanics such as twin bosses needing to be killed simultaneously or else one would enrage and kill everyone if he sees his mate going down faster. Bosses that could HEAR where you are and aggro you if you made a step without thinking. Bosses that could pull you into another dimension. Etc.
All of these made fights fun. Trying to estimate your threat and sitting there dumbing down your DPS and twiddling your thumbs while your enmity goes down is not fun.
Here's the Razorgore fight:
http://www.youtube.com/watch?v=fR2soJtHF-Y
One of the earliest boss fights designed in WoW and it already had more depth than most things FFXI had to offer. A crapload of mobs spawned and Hunters had to kite up to 6 mobs each, while the rest of the Druids and Mages CC'd the rest, and the Warriors and Rogues killed them. All while mind controlling the boss to kill his own eggs.