In both private and public industries there has always been good and bad managers, but how do you define the good and the bad. Depending on the culture of the organisation a manager may be bad in one culture, but then good in another. To be a good manger you need to have a flexible approach and be able to adjust your skills to manage both the organisations culture and the staff at your command. Unfortunately it is assumed that a manager who appears to be good in one organisation, will be good in any organisation. But this is not true if they can not adapt their skills accordingly.
A manger good or bad, needs to have staff reporting to them, that they can trust. As many public organisation are so large these days, the person at the top can not be expected to know all that is happening in their organisation, but does need to accept responsibility and accountability for all that happens in the organisation. A very big responsibility to undertake, but they do get very well paid.
This can be applied to every level of management, with possibly the reference to very well paid. All staff need to have the courage to talk and report to their next management level and that level should always be available to listen to them. Then that level should have the courage to do like wise and so on until the top level is reached. any breakdown of that structure is almost certain to lead to disaster.
Unfortunately, these days, when all are trying to manage targets, the target becomes the priority and not the management/staff reporting structure. Maintain the structure and you are more likely to maintain the targets. and still provide a first class service.
In effect each management level is equating to the management of a small concern, where the top person can do all of this themselves.
But for this to occur the right people have to be in the right jobs and this is often not compatible with the extensive cronyism, that is also abundant these days.