I don't get what you're saying here; we NEED more magical DPS types or that we're asking for them?
BLU, for the most part, in all games it appears in is a physical-based mage. Most of its abilities in XI just happen to be Enhancing itself both defensively and physically (Mana Battery, Magic Carrot, Cocoon; Dual Wield, Quadratic Continuum, Thunderbolt).
It was basically strictly a melee DPS in XI; if they want it to be Enfeebling, that's fine and all, but I can't see a job in XIV be focused on JUST Enfeebling as those abilities are heavily nerfed on release in this game and are given way stricter decay rules, not to mention that implementing concepts such as disabling a monster's complete resistance to Enfeeblements for a short time would be considered OP in this type of game.
Also, most every job in this game is essentially a carbon copy of their previous iteration in XI (with the exceptions of SCH and SMN since they're based on the book-wielding ACN) weapons and gameplay-wise. To compare a possible iteration of BLU in XIV with XI is not really out of the ordinary; although DRK is a tank, it still uses a GS, even though its main weapon was a Scythe in XI. NIN still uses Daggers and SCH essentially made sense to use a book because they had access to the Grimoire in XI for using Addendum abilities.
I'm not saying it needs to be exactly as it is in XI, but to say that it shouldn't be is ridiculous since most jobs in XIV basically take from XI in both weapons and abilities anyway.
