Agreed, FF titles don't really do well with sequels. But I'm perfectly ok with side-content set in the same world but following different characters separate from the main cast. Sad that the closest we got to that was Dirge of Cerberus... I think? Maybe XIII-2 counts but that went a little too crazy and didn't even seem to be part of the same world as the original, so...

I think the only reason really that I DON'T want a Vagrant Story sequel is that I love its battle mechanics. And after seeing what happened to Parasite Eve, which had very similar mechanics in the first game, I've grown to not trust any potential devs not to destroy the system it touts in favor of more modernized mechanics.
...Oh also I guess there's some concern about the color palette. You know how protective I am of colors. And modern games seem to all completely miss the mark in terms of attractive color choices, aside from maybe Monster Hunter World and Dragon's Dogma.