European houses are not designed to withstand American disasters. A brick house that can survive a M8.5 earthquake, which is the safety standard where I live, will be almost purely steel structurally and very expensive to build. The brick would be decorative, which can be (and is) done on a wood frame.
Then you have to consider how quickly development took place by comparison, and the collective degree of certainty among the original buyers on whether or not they would be able to afford to stay very long anyway.
So many come there just to give California a try since it's supposed to be the golden state, who are depending completely on the occurrence of good fortune within a limited amount of time before they would expect to return to states with less-expensive hometowns in mostly less fire-prone environments.
This would influence what kind of home they would expect to be suitable for their needs to begin with, and how long it might need to endure.