I play Final Fantasy because the vast majority of the time the games aren't MMOs. This saves me money (no monthly fee) and as the games are nice and long and often of the highest calibre I know I'm getting my money's worth.

I do love the rare MMO without monthly fees (talking decent rather than the all too common free, ingame purchase supported lesser titles) like Guild Wars back when I used to play, but it's not often I can justify paying a monthly fee for a game, especially when it's not uncommon for me to have a large backlog of unplayed games which'd have my attention over the MMO regardless.