Can this keep a house on its land during a 7+ earthquake? A lot depends on how close the house is to the epicenter, the type of shaking, the quality of the beams, etc.
This is used when a house is taller than it is wider. Designed to not allow the house to tip over. However, I can see where the house, particularly if its wood framed, could snap in half.
All I'm saying is bolting isn't definitive, and should not be stated by these companies as a live or die scenario to a home owner. Besides which, the $-to-rip off potential is huge. The USGS suggests bolting should cost $1,000 per a normal-sized house - probably 2,500 square feet. I've seen quotes of $5,000 - $10,000.