Why do people want Blue Mage in this game?

[dinnertime]

Or they'd just make Blue Mage into some new class and betray it's namesake. Like Dark Knight, Summoner and what have you. Pffft.

So do you really want it? If you don't mind more classes to play as then great. But if you come in expecting Blue Mage from previous incarnations of the FF franchise then you'll be so disappointed.

Uhh you're wrong, well partially.
Dark Knight has Blood Weapon and skills that not really drain, but restore HP and MP, but doesn't have the true Souleater gimmick of sacrificing HP.
Summoner can summon eikons, which are the Egi.