We should first start out by noting that it is difficult to build basements in the type of soil that much of Oklahoma rests on. Wet damp clays expand and contract a lot, so you are at risk of having your house squeezed-pulled apart from below. That is likely why Auntie Em and company went outside to get to their shelter.
But still, people still had their little shelters.
That is changing.
Why Aren't There More Storm Cellars in Oklahoma
Megan Garber, The Atlantic, 21 May 2013 (hat tip: NC)
Sheltering, in other words, is moving from an individual concern to a collective one. And while community shelters still aren't the norm -- Moore, for example, has no official public shelter, on the logic that sheltering-in-place is often the most prudent strategy -- that shift makes sense. More public shelters will mean more options for people when tornadoes form, as they do, with little notice. One reason tornadoes prove so deadly now is that, given the spread of the suburbs, their funnels simply stand a better chance of touching down where people are. Tornadoes used to hit farmland; now, that same land is increasingly concentrated with people. If the suburbs keep expanding, Paul Douglas put it, "we're going to see more of this."
Now, the behavior of coastal folks in relation to the threat from hurricanes is egregious enough that I want to make the strong point that there is nothing unusual about this "worry when it happens" and "why didn't/doesn't the government do something about it" attitude.
One of the tricks of the story is to set the bar for protection so high that few individuals could ever afford a shelter. You don't need missile proof shelters. You aren't going to be in their for days, a covered trench, a root cellar without the supply space, would work in most circumstances. Even a tiny closet made of poured cmu block reinforced with rebar, above ground would probably suffice. And it is easy enough to build that, building code officials aside, you could do one yourself over time.
But its hopeless. We are were we are, and you aren't going to turn the wheel back.