Well, two questions need to be asked here:
- How well does it appeal to the Fire Emblem / SMT audience?
- How well does it appeal to the WiiU audience in Japan?
Those two are some hard checks for potential sales. If it was an SRPG it definitely would have appealed more to the Fire Emblem audience, if it was more obvious about its' SMT themes (if there are many), it definitely would have appealed more to the Shin Megami Tensei crowd.
Honestly looking at it I don't think we are the only ones who got some heavy Persona vibes from it in the first place, issue with that being however I assume that audience to be rather part of Playstation's audience instead of Nintendo's.