I agree with most of what you said. I guess the reason this still comes up is because of what we as a fan base expected from FFXIII. It had the name and heritage to get it going yet failed in many people's minds in so many way. If it was just a game released without the FF name it might have done better because we didn't expect anything of it.
This said, one gripe I have with it, beside much of what is discussed, is the lack of steam punk. It was cyber punk. This is why it didn't fit.
Hmm, pie.