Why are people blaming the head for teachers under performing? Are teachers not autonomous professionals responsible for their own actions or in-actions? It really hasn't been the time for performance management, has it

Obviously managers have their role to play, but ultimately if someone is under-performing, they need to take responsibility for that.
Anyway I also don't agree with the head going on and making these comments. There are lazy people in every single profession, but you don't see other managers taking it to the media. They deal with it through the proper channels, professionally. It really is very silly to be further adding fuel to the current criticism teachers are getting. For goodness sake, give teachers a break!