I'm sure whoever first suggested a single, consolidated Disney Springs bus loop away from the Marketplace was likely praised. It's a smart business decision. It's also nothing new. Just look at Universal Orlando. From the transportation point (the parking garages) to your destination (the theme parks), you have to go through CityWalk.
I also think your claim that the majority of WDW resort guests only want to visit the Marketplace area is dubious. Every time I've visited Disney Springs, the non-Marketplace areas are full of people...particularly the West Side and The Landing.