For CR, then monorail builds up a long line for guests returning to all 3 resorts. Many opt to take the walking path and get back to the hotel sooner than they would by monorail.
Given the choice of boat and bus you often can judge if the boat will be boarding quickly, and if there is a crowd waiting head for the bus and it's a wait for the bus and a ride but rarely will you find buses full and waiting for a second bus like can happen at some.