It's a north american thing. Houses here get built in literal days as opposed months. Timber is also cheaper and more readily available than alternatives. Further to that, in colder areas like where I am in Saskatchewan, timber framed houses are often better insulated or have better r value than brick or block homes.
Looking at the picture, I do think the roof could be pretty critical here. Majority of roofs are asphalt tile and would be pretty susceptible to catching on fire from falling embers.