Why did america abandon its fallout shelters?

During the dark days of the cold war, America was in great fear of a large-scale nuclear war. Because of this, they decided to build and designate fallout shelters all across America, however we haven't heard news about these shelters for a very long time. Is America no longer scared?

Scientists across the globe know for a fact that at least 90% of the shelters designated by the USA were not sufficient to withstand anything near as destructive as a nuclear weapon. Speculation suggested these shelters were constructed only to put public concern to rest, on the other hand there are many darker theories as to why America abandoned its fallout shelters.

One of the most famed apocalypse theories is when the world becomes sickened with nuclear fallout caused by  war. In fact, this theory was taken so seriously, America's government invested millions of dollars in fallout shelters. Will America ever reveal the reason for the desertion of its fallout shelters?