Well think about it this way. Raid blu already has a "bore for the sake of balance" rotation. 50% of their skills are repeats with different targeting and a whole bunch just dont work in raids/trials, so you basically get locked into THE blu rotation (yes there is one, its not as free form as people would have you think).
So the question is if its rotation already exists and is somewhat balanced (which it is, 70 blu does comparable dps to level 70 jobs if you turn off dps mimicry), why cant you just be locked into that already existing skillset for current content.