I think Brendan hit the piggy on the nose here...this isn't a family minivan - it's a grown-up person's ride.
I had a friend in law school whose father was wealthy, fat, and incapable of bending. He drove a Chrysler T&C because it was easier to get in/out of and gave him enough cargo capacity for his Krispy Kreme runs.
So, too, is my Edmonton Buddy's father a fan of plush, big rides. His wife now drives the Santa Fe XL, but they often are left wanting for more space. This would be ideal since they don't often use more seats, but want more space and luxury. It helps that they like the Korean brands.
I do see the market for this...but how big is it?