That information doesn't make ANY sense. Notwithstanding that there are NO buses from resort-to-resort, but there ARE direct buses between each resort and Downtown Disney (making that travel time information inane

), there is DIRECT transportation between each park and each resort. Granted, some resorts share buses, but Coronado Springs is not one of them.
The Unofficial Guide has (or had, I haven't got the 2007 edition memorized yet) a good comparison chart showing the shortest-to-longest transit time range using your own vehicle vs. Disney transportation.
From the 2004 edition, Disney transit time ranges only since you're apparently not going to have a car, in minutes:
CSR to Animal Kingdom: 8 - 31
CSR to Disney/MGM Studios: 7 - 27
CSR to Epcot: 8 - 28
CSR to Magic Kingdom: 11 - 31
Shortest time based on bus being at the stop when you get to it, leaving directly from that stop to the park, average or better wait-times at traffic lights.
Longest time based on JUST missing bus and having to wait the standard twenty minute interval for the next bus.
Oh, wait, now I remember what might have been the (OLD) basis for the directions to change buses at Boardwalk Inn: When CSR first opened, and for several years, there was direct transportation between there and the Boardwalk, in deference to the expected large contingency of convention Guests who'd be seeking evening entertainment following a day of seminars.