1. Big school: They've worked their way up for this. They started working hard and being the "little guy on the totem pole." Their job should be, at this point, to be the director of the top bands (marching and concert), dealing with all the paperwork, and being a manager/mentor to all the other directors. That's what takes all the time. They are listening to other classes, and offering notes, taking kids individually on an occasional basis, etc. It's a lot of hard work that often goes unnoticed.
2. Small school: They're lazy. They can't just do the head director job that they could at a big school. They have to be more actively involved in all aspects of the program because the staff is so much smaller while still doing all the admin stuff.