The chances are hardly equal around the country.
Tornadoes have very narrow damage swaths and the odds of an individual house even in the middle of Oklahoma being destroyed by a tornado in the next 100 years are miniscule.
The single Northridge quake in 1994, which wasn't all that big, did many times more dollar value damage alone than every tornado to ever hit the United States.
There's a reason nobody has to pay extra for special "tornado insurance" even in the Midwest. It's not that much of a loss threat.