I don't think he's necessarily wrong, though. XIII's lore is quite interesting and certainly very complex. It's just not used well in the games and it's all in the side material, which in itself is a trend worth criticizing, I think. Having to read supplemental material outside and unrelated to the game to get the most out of it is silly, no matter the series. There's a line between being self-contained with just extra material that explains more of events or background (FFVII is a good example) and reliance on explaining the main plot through outside material (XIII, Xenogears, Danganronpa, arguably Chrono Cross, so on).
That being said, and I said it earlier in the thread, I think LR would have been a better game had it not been directly connected to the original XIII and XIII-2. It cheapens the world the game takes place in, because I found it genuinely interesting. The connection to the previous games felt tacked on in comparison.
XI is probably the only game in the series that has more complex worldbuilding than XIII. But XI also has had more than 10 years of updates and expansions to build, so it's not a particularly fair comparison.