No. Just look at the postmortem engineering reports on bridges which have collapsed (due to crappy inspections and maintenance, or being hit by a vehicle, or fire, or ...). Understanding which parts of rusted & crumbling old bridges are critical (to keeping them standing) is extremely important. Because the real world has many, many such bridges. And even fresh "Rescue workers are still pulling bodies from the collapsed bridge!" headlines seldom motivate the politicians to provide enough resources for inspections & maintenance & protection.
Depends on the meaning of "civil defense" in the top-level comment. If that means "protecting civilians & civilian infrastructure from military or paramilitary attack", then "No" is correct.
If "civil defense" is so broadly defined that it includes "protecting from normal aging, weathering, and neglected maintenance", then "Yes".
(Admission: My sense of such usages may be kinda old. Dad was a Civil Defense Officer in WWII, specializing in poison gas attacks.)
Perhaps the root cause here is due to conventional current being opposite the actual, literal flow. GP likely wanted to deny the implied sarcasm of parent comment, and I could see how it might be read either way. Tone in text is hard.
Ha, I have a good engineer friend who often plays devil's advocate and he sometimes seems to reflexively respond with a disagreeing statement even if he is agreeing with the majority of what is being discussed.