There's a popular urban legend that Square was on the verge of going under and expected the game to be their last, hence the title, but in reality what happened was that the creator wanted the game to initialize as FF and his first choice, Fighting Fantasy, was already taken. He was planning on retiring after the game was published, though, so he eventually settled on Final Fantasy. Still didn't work out, though, because he directed 1-5 and then contributed to 6-10.