I don't think it's a bad game. But it's more of a 6 or 7 than 8.5 or 9 out of 10.
I feel like most of the people who played it are (a) new to turn based strategy and (b) Fire Emblem fans. Both perspectives have a propensity to forgive flaws that people exposed to other TBS/RPG's wouldn't.
It's an overall good strategy game, but there are flaws that sour it:
1. Weak cliche forgettable story
2. The game presents clustering as the only acceptable strategy and rewards you for complying with it by giving you insanely overpowered strength
3. Difficulty inconsistently varies between super easy and cheap. In a game where characters are supposed to be indispensable, characters often die in one hit.
4. Level design is painfully lazy. They are basically open fields with some walls a few (overall) inconsequential forts peppered in.
5. The story is quite short for an RPG. I completed it in 15 hours. No online or offline multiplayer. Very few additional challenges aside from derivative grind modes. And plastered paid DLC ads to salt the wound.