Basing your opinion off of "user scores" is a pretty bad metric to go by.
Call of Duty: Infinite Warfare, for example, has a 3.5 user score on Metacritic. This is because the series is notorious for a lot of people dismissing it as a repetitive and tired franchise that fails to innovate. A vast majority of these people giving it a low score have simply never played the game. And the ones that have are exaggerating its problems, as it is far from a terrible game. A 3.5 score should only be reserved for games which have severe technical flaws or other terrible problems. The game doesn't deserve a bad score just because of its title alone.
With respect to FFXIII a lot of people have adopted a similar mentality. They hear others complaining about it being a "corridor simulator" and give it low score reviews despite either not having played the game, or exaggerating the issues with the game. Some people will call a game "boring" and give it a score of 0. It isn't justified.
I disagree. Despite its supposed linearity issues, I never heard nearly as much complaining about XIII as I have about XV. I browse NeoGAF, reddit, and sometimes even /v/ and XV seems to be a disappointing entry by unanimous decision. Of course this doesn't account for the whole 'XIII vs XV' debate, and it's entirely my interpretation of the general consensus. It also doesn't account for people who have positive feelings about the game as they aren't as likely to post about it.
I really don't think XV is a bad game. In fact there are elements of it that I absolutely love. But in terms of overall quality I feel that XV was a disappointment.