The driver on the bus says "please move back", "Please move back" ...
All through the town.
If people standing moved as far back as they could, the bus would not be stationary at each stop for as long. (Transit experts call this "dwell time").
It is not necessary for parents to hold 8 year olds and up on their laps.
As for number of stops:
Caribbean Beach: 8 I think.
Port Orleans (both): 5
All Stars: 3
It seems to me that resorts that don't share buses (e.g. Animal Kingdom Lodge, Coronado Springs ) tend to have less frequent service during more of the off hours.
Coming back from the park at closing, there is the advantage of not having too many resort stops per bus since the dwell time goes up as people getting off at the first few stops have to squeeze by so many people not getting off. But I think WDW has this all figured out. This is not a problem going to the park, everybody gets off at once.
One unofficial guide to WDW (I had the 1996 edition) confirms that driving between resort and park is almost always quicker, the primary exception being to and from Magic Kingdom because of the need to transfer to monorail or ferry. A comprehensive list of trips and estimated best and worst case travel times was published and sure enough, some worst case times (involving transfers) were more than one hour.
Disney hints:
http://members.aol.com/ajaynejr/disney.htm
<small>
9/65
Disneyland
3/75 World Inn (now Doubletree Club)
4/85 Kon-Tiki (now Econolodge Hawaiian)
'80s Disneyland once or twice
7/94 Dixie Landings (now Port Orleans Riverside)
9/97 All Star Music
11/98 ASMu & first premium annual pass
12/98 Knights Inn on 192
9/99 All Star Movies
12/00 All Star Sports & PAP#2
9/01 ASSp
11/01 ASSp
1/03 Motel 6 & ASSp & PAP#3
11/03 ASMu planned
</small>