The problem with the passive voice is that we tend to use it excessively. Because it shifts attention to the logical object by making the logical object into the grammatical subject, we do not notice the logical subject (whoever is doing the thing that gets done). Bureaucrats in particular love to use this sort of language because it literally avoids assigning responsibility.
A decision has been made to close the left lanes of the Beltway during
That preceding sentence tidily avoids giving the poor motorists, stuck in traffic, someone specific to hate with an unending and murderous rage. :)
As a technical writer, I have learned to write very precisely. If it is important that the logical subject is unimportant, then I avoid discussing the logical subject and possibly thereby diverting attention.
Passengers are advised to keep their passports ready.
In the preceding case, it does not much matter who is doing the advising, because it is good advice, and that's the key thing that is to be noted.
To accomplish this sort of writing, the passive voice is best. Otherwise, if the logical subject is important or discussing the logical subject just does not matter, then I use an active voice.
The general drift of Strunk & White is to say what you mean and mean what you say, and do so precisely and clearly. To use the example provided with the question, a rewrite might be useful depending on the purpose of the text. If I did not like the security measures in question and wanted everyone to know who is to blame, I would write:
To combat this, the Administration has implemented new security
measures such as identification checks and on-site police officers.
Likewise, I would rewrite the text into the active voice if it were for a news piece and needed to convey the 5 W's and H: who, what, when, where, why, and how. The key thing about the passive voice is that it leaves out a "who". Oftentimes, it feels more formal because doing so creates something of a distance and delay between the reader and the subject, whereas the active voice creates an immediacy and urgency.
So no, the passive voice is not bad grammar, though in many circumstances it is bad form or style - evasive where directness is called for, aloof where immediacy is more appropriate, etc.