Is that actually a bunch of anonymous quotes from 2chan you linked?
Well, I beat FFXIII apparently lacking understanding of the battle system. Is that really a difficult game then? After all, none of the fights are genuinely hard, the game just forces you to figure out which shifts to use when to proceed. Hell, I used Army of One to build stagger on Orphan's final form, switching between relentless assault then aggression and combat clinic to heal up.You can stagger it faster by using proper rav abilities and not army of one which is just an animation time sink. Your lack of knowledge of the XIII battle system is showing.
If your suggestion that FFXIII is super difficult is based on the fact that most people see the game over screen a lot, it's because the retry system was clearly designed that way for people to learn the fights. Kind of like Dark Souls - dying is a learning mechanism, not a fail state. As most people come to realise, Dark Souls isn't actually as hard as people suggest, it's more about understanding the game and how things work.
Yet even FF veterans constantly pull up Seymour Flux and Yuna as two of the hardest boss fights ever.The game you're hyping up as about as much complexity as a mario game. Flat out if you where the proper level and didn't one shot every boss in X it was your first rpg or you're bad at rpgs.