I've seen quite a lot of love for it. But it's not true that no barbarian subclasses do anything outside of raging. The Totem Warrior gets magic rituals, for instance. Certainly no reason a new subclass couldn't provide more subtle power outside of rage, and just make those features more potent while Raging.
Besides which, I wouldn't want the concept to just be "a dragon guy" all the time. A transformation is exactly the hook I'd be looking for in a presentation of the concept, even if it were a class.