I don't think it makes any rational sense at all to live your life based on weather patterns or relative safety based on the weather. And if you use such criteria for choosing where to raise your kids, where does that criteria stop? Where is someone most likely to die for no good reason.....Chicago, along the border, or Oklahoma City? I'll take Oklahoma City any day.
Number of U.S. tornadoes per state (from Wikipedia)
These figures, reported by the National Climatic Data Center for the period between January 1, 1950 and July 31, 2009, show the ten most affected states. As reports are taken from individual counties within States, sometimes the same tornado can be reported more than once as it crosses county lines.
So looking at the data above, are you actually "safer" in Oklahoma than in Kansas? Of course not....it's the weather. You never know what might happen. One of the worst tornadoes in recent memory was in Joplin, but they are pretty far down the list. Should NOBODY live in any of these states because of what "might" happen? Just because a devastating event happens doesn't mean it's a "good" chance of it happening. Bad weather and other events can strike anywhere, anytime.
If someone's looking for a reason not to live somewhere, I believe something like extremely high state income taxes would be more rational than moving because of potentially bad weather.