No, you're just confused. Let me see if I can un-confuse you with a scenario: Ask yourself this question -- what magnitude earthquake could said bridge withstand as you drove across it. There absolutely *is* a point at which it'll collapse... Guaranteed. And a whole bunch of "Bridge DEATH PANEL members" made up some engineering guidelines for what reasonable bridge building standards are.

These are all life-and-death decisions, and the reason you make standards up in advance is so that the emotion of a singular situation doesn't cause you to constantly make bad decisions. This holds for bridge building, and for decisions about what extrordinary measures should be used to attempt to save individual lives.