Why wouldn't the second half of FFVI have existed without DQ?

I've actually been thinking about getting into DQ now that there are a few of them going to be available on the DS. One of the more recent ones for PS2 or 3 looked fun a while back.

Oh, and actually, I REALLY don't care much for the second half of FFVI. It's too optional. It feels like after waking up on the beach and finding out the world was destroyed, the game lost all purpose.