Metallic Linings
People born without the innate ability to make rational decisions regarding their environment (i.e. "common sense") are good for those of us who are. They create the intellectual and social friction that only makes the rest of us smarter and stronger. Without them, we would never have to strive to lead by example. We would never have to go out of our way to back-fill the work they neglected.
We often wade waist-deep into the swamp of their misadventures. It's frustrating, but we emerge the stronger for it.