Peoplemovers or anything that requires a beamway or track will always be more costly than a bus that runs on existing roads. Boats tax the waterways as well.
Many posters have pointed out that the system needs to be tuned, technology could be intuitively used much better, the waiting could be masked by activity and the bus experience itself could be something fun (an attraction in itself) that would justify the wait.
BTW- I used to work as a creative consultant/designer on Mtv's "Pimp my Ride". You'd have to make something unique out of the most banal, thrashed cars and make the transformation worth watching for a half hour. Anything is possible, and if you took the attitude and "pimped" those busses out "Disney style" they could be something guests would chase after and beg to ride. They'd be collectible toys in themselves. Imagine Dad.."Hey honey, we rode on "Peter Panavision" it was awesome inside with all these screens! and pirate skull seats" Their kid says.."So what, we got on the Grim Grinning Coach with the purple lighting inside, we even had a ghost host driving!". Virgin America airlines does this well making the plane feel like a nightclub with magenta lighting and chill music as you board. They serve Absinthe in first class! They name the planes too like "Lady Penelope" with a pinup girl on the nose. It's just that no one sees these busses as anything beyond a bus. Virgin took a generic plane and made it fun. Little or no imagination is used on the notion of transportation (TDR and Cruise ship busses are better). They don't have to be over the top either, just beyond expectation enough to reverse the pall of the waiting. No one seems to care and it's a big link in the chain of your experience on the property.
It would be nice to exceed expectation with a better experience. To me as a driver, the noise of the buses in traffic is totally obnoxious and that should be solved too. Here in Hollywood, they use open top double decker busses from London for sightseeing and people seem to like them alot. A combination of improvements could make the situation a bit better right away.
Having said that, give me a Peoplemover or a Monorail any day!