Tactically, abandoning any people, or killing people who refused to come along, just doesn't make sense. But this show doesn't try to make sense.
No, it does not.
No, I don't cheer for him. The writers of this show have made a mistake in making every single character unlikable to downright contemptible. I realize that's sort of a takeaway from a lot of modern TV dramas, but it's a mistake.
On target: modern TV producers/writers seem to think being "real" translates as everyone being free of a true moral guide (or having it ripped to the point of not mattering much *cough*Rick Grimes*cough*), and Director of Interrogation Salazar fits that modern TV leaning.
Military thinking - deprive the enemy (the zombie horde) of potential weapons(live humans).
Except that kind of thinking would only lead to killing every living person, probably including the military. It seems like this specific directive only has to do with the high populated areas getting out of control, hence why there would be a retreat to somewhere else. I'm just not sure where that is, and I'm guessing we're not really going to see that anyways. I just don't understand why they don't bother to bring some of the people from the safe zones with them to wherever they're going.
It could be a number of reasons:
1. Lowering the risk of anarchy. We already see the anger directed at the military.
2. In a crisis situation with no known end-date, clamping down on food and medical resources (beyond the makeshift hospital) would be of great concern.
The cliche, evil military stuff is boring. It makes what the Governor did to that military group make him look like a good guy. It even makes sense. They're almost treated as if they aren't even people, just walking cliches. Fear the walking cliches.
Quoted for truth---but then again, that has been a running cliche in TV for decades. Most of the evil people will ever encounter rests firmly among the general population day after day, but there is a clear bias with some in entertainment to paint the military (or any armed authority) as evil, with few to no contrasts.
At least the original Dawn of the Dead balanced this with illustrating the difference between the rogue National Guard killer and one half of the protagonists in the form of Peter and Roger, but in FTWD, its the same old, same old.
As you so accurately observed, Fear the Walking Cliches.