WoW started failing for a number of reasons. One of them started when they starting worrying about "cookie-cutter" optimal specs. (Or some would call it meta) which is dumb, as something will always be the best (highest dps) even WoW had them, but people were not excluded because of a "meta" you couldn't be picky or choosy.

WoW only had a few missteps with its raid design, but otherwise was well thought out and made with a certain degree of care. The reason for this honestly is because rotations for most classes, while can be busy, was more straight forward, so the skill was in dealing with the mechanics, ensuring your dps uptime both physically and your DoTs, tanks managing aggro and boss/add positioning. Healers had to synergize with each other to keep people alive (also a person being able to solo heal in some fights was AMAZING). No one cared about a tanks or healers dps, there was plenty to heal, and any down time you were conserving mana. Tanks had other concerns but they often did some semblance of dps (dps = aggro).

Do i want ff14 to be WoW? No, i dont play ff14 for its raids anyway, if i go with friends....cool... if not... meh, im here for friends...and some pvp >.> i left my more hardcore raiding behind in WoW. but if ff14 DID take some pages out of WoWs book.... when it comes to raid design, id probably be more serious about going to do them.