Average user scores can also be skewed by people rating it on the extremes just to affect the score. Another measure is the distribution of positive/neutral/negative reviews. Here's how the last FF games stack up:

FFXII: 68%/16%/16%
FFXIII: 62%/16%/22%
FFXV: 72%/10%/18%

XV has more positive ratings then the two prior games but less neutral ratings, meaning people were more likely to love it or hate it. Overall, though, it's hard to argue that XV has been received worse than XIII or even XII by fans.