Well around here we have a bus service that runs once a week, get on it in the morning to go to the town and either catch it back in the afternoon or wait another week
Having said that, i have previously lived on Europe's (and possibly the worlds) busiest bus route in Manchester, where there is regularly 3 double decker buses at each stop, and as one pulls out another pulls in so i have experienced zero wait time for a bus as well
At WDW i dont find the wait times excessively long, there are occasions when the wait is long, but that is bound to happen on a system that is not run to a set schedule but that is manually controlled with the number of buses running and destinations that they go to, based on best guesses of route demand (ie EMH in MK 80% of early morning buses to there then)
The disadvantage that Disney has over a Metro system is that every origin (hotel) has to serve every primary destination (park,waterpark, DTD) whereas a Metro system does not it is up to the user to ride from their destination to an exchange point (or two or three) change to another mass transport, and then to their final destination (the way it works for hotel to hotel), but because Disney is not set up that way it is inefficient to do it that way, you could quite easily drive for 15 minutes past where you want to be
the system could be improved dramatically and quite easily just by having an ETA for each bus at each stop.
My perception of wait times might be off as we regularly decide to get on the first bus that comes to the resort, if we havent got plans for the day (unless its a waterpark bus) and i know sometimes you can be waiting for an Epcot bus for example and see 3 buses for everywhere else first
If we have a dinner reservation at another hotel, we either drive over there if we have a rental car, and are cutting it fine (or taxi if no rental car) but in general we leave in plenty of time as we like exploring the other resorts,, and can happily spend an hour or more at them before a meal