Definitely sounds likes like a section leader in Scouts, I had the same crap for 11 years, totally unappreciated best thing I did was call it a day, all you seem to do is provide a cheap baby sitting service, it was always the same one or two parents that would help, the rest were off quicker than a scalded cat if they thought they might have to help.
They don't see the meetings, training, first aid courses, planning, buying stuff sorting out the programme & buying the badges, giving up weekends at camp and planning the menus the kids will eat and the activities, they think it just happens like magic.