The blue mage spells problem is sort of a challenge from the perspective of a game developer. Ideally, we want Spell A and Spell B at point X to be "choices", but given the nuances in how the game works in combat if Spell A does even a small bit more damage than spell B, spell A will be used exclusively over spell B. Then imagine having this situation happening with 50 or more unique abilities they can pick up: The QA team would be spending more time testing Blue Mage for balance purposes than the entirety of the non-blue mage classes.

So the path to making Blue Mage legitimate would mean axing a ton of spells from the list to get it down to a core few, and then at that point we're no longer really blue mages.