What about protecting their IP? Putting out a game when you KNOW it won't sell well and when it will get bashed by reviewers. They are damaging the Final Fantasy brand...is that worth a few extra profits?
The thing is that one could assume that after XIII they would stop it right there and focus on Versus, XIV and XV. But, then they started with the sequels, and people somehow responded well to them, it appears that they have a really strong IP that will sell even if their previous iterations are not at a great level. Yes, they may not sell XII numbers, but they sold way more than they deserve.