Administrators do have to deal with parents, and with the press, and with the police, etc. I'm not saying their job is more important than teaching, but they will be the ones facing the public when anything bad or embarrassing happens at the school.
I remember reading an article of Michelle Rhee when she was head of Washington DC School district. At beginning of her term, she got lost in the district HQ and walked into a room where a lady was sitting in front of a computer. Rhee asked what her job was, and she couldn't answer. And soon enough, a purge of the HQ district office was implemented.
You can agree with her or not, but no doubt there is a lot of unnecessary people on payroll in places like school district HQ.