Is it really worse than 13 or at least in that ballpark?
This game is objectively better than XIII in just about every area,
especially if you're judging XV against its 2016 peers compared to XIII against its 2009 peers. I'd say that XIII was a more
polished game, certainly. But that's a meaningless thing when you consider how barren XIII was mechanically as a Final Fantasy or even as an RPG. It's like saying GTA2 is more polished than GTA3. True, but meaningless.
XV's deeper issues are mainly with pacing and what appears to be a story that was rushed / chopped up / condensed too much. The delivery of the plot falters with varying degree across the title, but there's nothing as cheesy or just outright bad as some of the stuff XIII intentionally does, and what's there definitely works as intended. As an added bonus, there is no "Real heroes don't need plans", or "We'll change the future!", or "We live to make the impossible possible!" anime dumbshit present in the writing.
The combat is the most subjective thing. The overall game design is Square Enix typical in emergent depth,
easily my favorite FF battle system in the entire series, but it's not without its flaws. The camera can be
truly horrible at times, and can ruin some of the game's best moments. But when you get used to the battle system in this game, it just meshes and flows so well, and there is alot of unique content, awesome bosses and just cool stuff to see in the open world. And FFXV's hidden dungeons are simply amazing.
Everything else is just long-running fanbase bias, a dash of that trademark GAF hyperbole, and your typical open-world hangups. I haven't enjoyed a first playthrough of an FF game this much since 7 or 10, and I havent sunk this many hours into an FF game since FF12.