The real question is do we want buildings to survive 200 years? In 200 years building technology might have advanced far enough that everything is carbon fiber concrete or something far superior. People look at degradation of a structure as some kind of serious issue, but it can also be seen as a positive.
To expand on this, will our descendants have the same demands in 200 years? Will a revolution in transportation dramatically change infrastructure needs? What will employment look like, how will businesses operate? Will citizens want the structures we build in the locations we build them?
The author suggests we build structures to stand the test of time and addresses structural, economic, and environmental needs, but not societal ones. The Moai referenced are not artifacts because they weren't engineered well enough, they're artifacts because they outlived the societies that built them.
