The original intent was for DTD/Disney Springs buses to serve as an option for Intra-resort travel. If you board any theme park bus at the Grandstand stop you can ride it to any other stop in the resort, finishing at The Springs before it departs for the park. Disney Springs buses would stop at The Springs first, and could then be used to travel from Springs to any other stop in the resort.
OKW does something similar with DS buses. Last I heard, they would stop at the Hospitality House when entering the resort rather than departing so you could board a DS bus at the HH and get to any other section of the resort.