It's not just computers. Sudden loss of power is bad for all electronic equipment. I've got external battery backup and power conditioning on every computer and tv set in the house, to allow an orderly shut down in a power failure, and at least once it's saved a $2000 tv set. A power surge and failure fried the backup's electronics, but it's only $100 to replace. Not an inconsiderable amount, but way better than $2000.