Honestly I don't think it is practical unless we are basically saying the exact same quests each day for a Job and only one or two cut scenes total. Otherwise the work required to develop 15 different versions that are the equivalent of Beast tribes just isn't feasible. It took the entire 3.x cycle to get 3 beast tribes done. Your talking about 15 different sets of quests in one patch. That if we leave out Crafters and Gatherers completely. If we add them your talking 26 different sets.

There is also the issue that for a lot of players they will only ever see a few of the quest sets. I don't see many people lvling a Job to 70 just so they can do a daily quest set.