Comment by kulkarnic

The rational reason we don't build nuclear shelters anymore is because they're no longer effective. As weapon yields increased, it's become apparent that a concrete, underground hideout is not going to save you.

The irrational reason is that it's been 60+ years since atomic weapons were deployed, and we are confident the danger has passed. But really, there's plenty of weapons out there: http://www.motherjones.com/politics/2011/11/map-nuclear-bomb...