Most smartphone games essentially play themselves while you control from behind the scenes. Take Plants vs. Zombies, you set up the tactics and place your plants down and they fire their pellets and what not without you having to interact with them or a similar game, Crystal Defenders by Square Enix themselves, a tower defence game. All these aren't about you selecting how your guys attack but where and what they attack. Final Fantasy XIII is kinda like that but on a console - and way higher budget.
The field map is also similar in Final Fantasy XIII, taking a queue from games like Plants Vs. Zombies or Angry Birds, they're simply level after level, there's no towns, no-one to talk to because they're unnecessary, you can access a store between turns on Jetpack Joyride, using money earned from the levels. The RPG elements are, for lack of a better word, dumbed down in mobile games, they're few and far between. This is similar to Final Fantasy XIII's field map, it's one long corridor taking you from one area to the next, there are no real towns or NPCs to interact with. On a console game where you sit down and play it for hours expected to get involved in the story and the gameplay. However on a mobile game you sit down a blast through a few levels on your way to work on the train. You can kinda do that with FF13, because there's no reason to sit down.
So with that, I ask the question; would Final Fantasy XIII have been a better game on smartphones? Probably, it wouldn't have had the budget, but it would have been a fun play through the game. There are significantly lower expectations for mobile gaming, which is just one of the many reasons I don't think mobile gaming is a threat to consoles. They're more like gaming from 1985, used to kill time, graphics aren't of paramount importance, they're just there to burn away the clock until you do something, which Final Fantasy XIII's gameplay is uniquely suited to, it's move from A to B, Level 1 to Level 2, kill some monsters with minimal reflex effort, so it's all about the pre-battle tactics and occasional quick switch up to keep the game exciting.
The sequels, the bizarrely named "XIII-2" and the 90s name inspired "Lightning Returns", are a different story because they went for more open elements in XIII-2 and more action elements in Lightning Returns, neither of which are well suited to the time-passing style of mobile gaming. I've already said my peace about Final Fantasy as a series in general, so it really comes down to this, do you think it could have been better received as a mobile game than as a console. If the high expectations hadn't been there and it had only been used as a game to pass the time, would it have been so reviled or at least so divisive. Would the Final Fantasy series reputation be in better shape? We'd already seen a bit of decline but Final Fantasy XIII was the, pun intended, Limit Break, it was the move that shattered the series dealing more damage than the previous titles had but it certainly wasn't what did all the damage.
Final Fantasy XIII's story still had it's issues, characters like Lightning, who became a giant mary-sue for the creators, Snow, who clearly had some kind of mental deficiency, and many of the other issues with characters like Hope, Vanille, Fang even Sahz, who was probably the best character in the series and criminally under-used, had his stereotypical afro and the weird Chocobo-baby in his hair... seriously, who thought that was a good idea. Worse even, who thought it was a good idea to have that chocobo grow up to become a half-naked woman-bird hybrid in the next game called Chocolina, seriously what crack were they smoking when they created Chocolina... Man this game blows...
On point again; story is kind of an afterthought in mobile games, they'd still be in a mobile version but lessened perhaps, which funnily enough if you watch Square Enix's 16 bit recap of XIII where it's quickly summarised, it actually makes far more sense than the actual game. So there we go, perhaps XIII wasn't a game that should have been on consoles but perhaps an interesting mobile game that casual players could enjoy because that seems to be more of the idea with the game, it appeals more to a casual audience.