It was all killed because two dynamics came together to push "the yale box": corporate america's love of cheap buildings (although the buildings are cheap to build but often nightmares to maintain and use... somebody else's problem) and the ideological purity spiraling post WW2 driven by the academic environment and the rise of abstract architectural criticism over the practical building arts.
post modernism acknowledged the failure of the yale box but, because going back to traditional building forms was unthinkable (of course), had to do ironic kitsch instead