It's funny you posted this, cc. I just watched one of the Potter films that kind of reminded me of that film. It was The Order of the Phoenix.
Dolores Umbridge, and the ministry decided Hogwarts was being run into the ground. The fanatical Umbridge was allowed to take over Hogwarts, denying that there was a very real threat out there in the form of Voldemort. She, along with the ministry, insisted the only problem was that the teachers, students, and Dumbledore with their lack of disciple, and conformity to The Ministry's decrees. She restricted everyone severely, and took away their ability to defend themselves.
The students decided not to just lie down and play along. They knew what the real threat was and some of them knew how to fight it. They got together, and the more seasoned students helped train the others to take on the threat to their way of life.
Naturally, in the movie, the good guys won. Umbridge, who was so detatched from reason, and the ministry, with their own set of agendas (which had nothing to do with what was actually best for the students, the school, or the wizard community) was exposed, and embarrased. The real enemy, Voldemort, was set back for a spell, and life progressed to the next film.
Ratched and Umbridge had a lot in common. The power, the fanaticism, the willingness to crush anyone who doesn't lie down for them. Doing it all while maintaining a phony smile. How could anyone love characters like them?
Now Marry Poppins was cool. She helped the kids stand up for themselves, and taught them to take care of themselves. Quite the opposite of the mean old lady characters of Ratched and Umbridge.