The Apollo missions had an even higher death to flight ratio...
The superb design was yoked in service to an outstanding mission of exploration and development.
The STS is a bastard design, the result of engineereing compromises that would have led Apollo team members to resign, and the result of granting the wishes of the pimps in Congress. The STS design is not in the service of any mission worth doing.
The deaths of the Challenger astronauts, the Challenger tourist, and the Columbia astronauts were for nothing.