The tragedy is that the difference isn't fundamental! It's not like S-E and Bioware are in two different leagues, or this is a David and Goliath comparison. The companies, at least as far as I can tell and correct me if I'm wrong, have access to similar resources, publicity, talent, and capital. They both have the capability to make a stellar, genre breaking game, and well, Bioware already has. Mass Effect 2 isn't the first time Bioware has struck gold, Mass Effect 1 was also great, and there's games like Dragon Age, and further back, Knights of the Old Republic.
I know FF-XIII hasn't come out yet. Nor am I expecting it to play like ME2 and be the same type of game. They aren't! But there are some aspects of quality that are universal.
Great voice acting (not just 'good', or 'good for a Japanese game.' I mean actual great voice acting. ME2 had Martin Sheen play the Illusive Man. Martin fucking Sheen! Get on the fucking ball with the voice acting, Japan. I know American voice actors aren't generally as devoted as Japanese ones, but good ones are out there. No more excuses.), an engaging setting, intuitive gameplay, a great plot, integration of the two (no separation of good plot/good gameplay, or ditching one in favor of the other. Games like Mass Effect proves that both can exist at the same time and even weave into each other), likable characters, and an overarching deal that you actually care about and throw yourself into, instead of just enjoying.
Mass Effect 2 gave me all of that, and so can Square Enix, if they get on the ball. But it's SE's misfortune that ME2 came out first, and well, they have a lot to live up to. Not just to me, but to everyone that likes both genres and plans to play both games.