If you've ever been to a Disney park, you know that the bus drivers have one of the most important jobs in the whole company. They transport guests to and from their hotels, parks and other destinations. They're not the most glamorous cast members, but they are critical to the entire operation. Unfortunately, the work that they do gets taken for granted by guests and often times they get frustrated with the system for reasons that are out of their control.
For example, many guests are in a rush to get to the park in the morning and the busses aren't fast enough for them. Similarly, when they're returning to their hotel at night, the buses are packed to the gills and they're standing the whole way. This is frustrating for the passengers and for the driver. The drivers are just trying to do their job and get the guests back to their rooms as safely as possible.
Another thing that can frustrate bus drivers is when guests try to jump the line and push ahead of other passengers. This is frustrating for the drivers because it slows down the loading process and it's also annoying to the other passengers.
Finally, some of the passengers can be rude and obnoxious. This is frustrating for the bus drivers because it's out of their control. Many of the bus drivers don't want to deal with the obnoxious passengers and they don't have time to get into arguments with them. This is why communication is so key for Disney's transportation department.