The Passive Voice is abused when the agent of the verb is not general and is indeed of consequence, but the writer wishes to obfuscate. Bureaucrats and politicians abuse the passive all the time, to hide responsibility.
Consider the following sentences:
The committee members, by a vote of 5 to 4, decided that the school nurse should immediately inform the police that Mr. Jenkins had been found smoking marijuana with several of his students.
It was decided that the authorities should be informed of an apparent misdemeanor.
The first sentence is longer. Well may it be—it is long because it delivers a great deal. It tells us quite a lot. It tells us who did the deciding, and that the decision was close. It tells us who was to do the informing. It tells us who had done what with whom. The second sentence obscures all that. Who decided? Who informed? We don’t know. We aren’t meant to know.
Or these sentences:
Several recommendations were made that were approved after discussion, after which a motion was made that further recommendations might be made in the future, contingent upon the success of the former.
We talked about hiring a janitor and a carpenter. We decided it was a good idea, and, if it worked out, we might hire an assistant for each.
No one can read more than a few sentences in the style of the first, without suffering anacephalic shock: one’s head explodes. (I made up that word.) That’s what the writer intends. The writer wants to make it as hard as possible for you, citizen, rube, peon, to understand what your betters are doing.