FE13 is okay.
They needed better plot structure, better characterization, with possibly fewer characters. Then again, it's not like Path of Radiance and Radiant Dawn didn't manage to give pretty much everyone a personality and a reason to care about them. Except Makalov, **** Makalov, I always kill Makalov first damn chance I get. FE13 also didn't manage to have a strong core like FE7, with Chrom and Robin being WAAAAAAAAY to underdeveloped. Chrom literally never grows. The closest thing he has to internal conflict is his insecurity in ever being as good an Exalt as his sister ... which never really goes away. He's a fine leader in his own right, but no one ever doubts him, he never faces any kind of major stumbling blocks ... he's always the noble, upright, leader of the Shepards. Contrast this with Hector and Uther in FE7.
The thing is, some people don't need to grow as much as most ... but they don't make the most interesting characters. The Hero's Journey/the monomyth/what have you is the single distilled essence of every story for a reason. You need to see someone go from point A to point B, to grow, to suffer, to feel, to overcome adversity or not, but learn and become a different character during the process. Chrom is static. Much like Eliwood, he suffers trials and loss but it never really changes who he is or takes him in an interesting direction (and dear lord, Eliwood had it much, much worse.) He could have become so overcome with anguish that he would neglect his royal duties and become a terrible ruler. He could never accepted his role as the exalt, leaving the throne empty as he continued to rove the countrysides as the leader of a militia that was the only thing keeping him sane, with companions rapidly losing faith in him. The Valm arc could have never existed, eschewed in favor of a Regna Ferox that seizes the opportunity to attack a weakened kingdom with an absentee ruler running from his demons, plunging the continent into turmoil as the Grimleal plot the ascension of their dark god.
Just ... there was so much potential to get better than what we got. What we got instead was a bland story where you actually have to search for the good characters and plot points, where the good stories arise as a by-product of sheer volume rather than being inherent to the game. More than the ridiculously imbalanced gameplay, that's why I didn't appreciate FE13. I'm glad it prevented the series from dying and drew in a new audience, but I don't think I'm being naive when I say it had the potential to be something much, much better.