I know that graphics are getting better, but imo, I think if they used the same graphics engine and battle system that was on say FFIX, but a completely new game, I think it would sell really well.
Well, they're trying to get around the constant graphical improvement machine as its killing their company.
There's a reason why we have sequels of 13. They're re-using the same engine and a lot of the same assets because of the very high cost of developing it all in-house. With the highest development budgets introduced with HD consoles, developers are trying to get more bang for their buck.
Also, they've tried do some original ideas and new games with Bravely Default (3DS) and Four Warriors of Light (DS). They're essentially FF games without the name. They're far more classic/traditional types of RPGs.