Isn't this a bit like getting too ahead of things? Des moine is a completely car focused area. Who cares if you make a walkable area, with lots of stores, etc. If people still need to drive there? Maybe the video missed mentioning that part, but you need dense housing, so that a huge group of people don't need to drive there to begin with.
This is like building a walkable area where no one lives, and no roads to get there and surprised everyone says it would suck because there's no roads to get there.