I think, tiggerdad, in the evening hours there is a direct MK - FW bus (along with the boat) to take people over for HDDR but in the morning there is NO direct bus to MK. Disney wants to make it easy to spend money whether it's for HDDR or over to Disney Springs in the evenings after the parks close to buy overpriced booze and souvenirs.
Same reason goes for the mornings when there is a direct boat from FW to the Contemp it's because they want to make it easy to get to Chef Mickey's for breakfast and not to take walkers to the CR dock and let them walk to MK.
After breakfast hours the FW-CR boat adds the WL and makes three stops then reverses direction after lunch. So it's not about convenience, per se, it's about the almighty dollar.
Bama Ed