When you strap people on top of hundreds of tons of explosives, and shoot them into space at thousands of miles per hour, there's an understanding that those who volunteer for such missions are taking a big risk. Test pilots, race car drivers, special forces soldiers, firemen, etc., etc., all know that risk comes with the job.

NASA's responsibility is to conduct a space program. Of course it tries to minimize risk, but eliminating it is impossible and counter to the whole enterprise.

The rescue rocket idea is/was untenable. There was no way the space facility could prep two vehicles simultaneously. The logistics of fueling up a rescue craft with liquid oxygen and rocket fuels (which takes weeks of planning and methodical prep), along with ensuing saturation of already-stretched ground support capacity, would actually increase the chances of disaster, while the cost would shut the program down cold.

Meanwhile, because the shuttles were not designed to dock with each other, an additional huge risk would be taken getting the vehicles to rendezvous, and somehow transfer the astronauts safely from one craft to another.

The space shuttle is the single most complex system ever designed by humans. Vectors for error multiply exponentially when you double the load on all the support systems.

Rockets blow up. They always have. That's their nature. If one can't accept that, don't be an astronaut.