Depending on where you are in the world, earthquakes are much rarer then insane storms. I'm speaking as a Floridian. I'm fairly ignorant on this issue, but would it be that difficult to use one or the other depending on which natural occurrence is more likely? Or is this also a cost issue?
"The North Carolina Utilities Commission
studied the cost of placing Duke Power’s distribution facilities underground and found it would
cost more than $41 billion, resulting in a 125 percent increase in customer rates."