Late to the BLU Party

[Andevom]

"
The argument that there can be no combos because BLU might not know all their Blue Magic falls flat, because there's no more reason for them to not learn their blue magic than there is for other jobs to not learn their abilities through job quests."

Except there is when Blue Mage is based entirely around hunting down and learning new abilities.
Its designed to be a challenge, its not going to be as easy as doing your next job quest, you'll spend weeks learning them.
They specifically said, in comparison to logos abilities, because each skill will be permanent and not disposable, that they need to be much harder to obtain.

You also wont necessarily learn then in any order. You might learn 1000 needles at lvl 5 while another Blue Mage doesnt learn it until lvl 47.
This is completely incompatible with a fixed rotation, and you'll see why when its released.

Not to mention, iconic spells like 1000 Needles would be virtually useless in an endgame setting. There would be a ton of "Congratulations on learning this spell you're never gonna use!" going around. At least the system currently being formulated *seems* to make it so you'll have a use for what you can learn.