If Challenger hadn't already made it obvious, the loss of Columbia showed the bankruptcy of a space program built around a tiny number of irreplacable spacecraft, flying to a one-of-a-kind space station, at astronomical operating costs.

The horrible secret of the Shuttle program is that the program would actually come out a lot better from an accident killing all the astronauts but with intact recovery of the Shuttle orbiter, than the other way around.

NASA has been running on inertia for a long time now. The current exploration program is a sad recycling of concepts that were scrapped after the Moon flights. Why scrapped? Because the R&D had been done, and there was nothing in it for NASA to keep turning out Saturns from assembly lines. NASA can keep in the R&D business by reinventing old designs from the ground up.

It's important to keep in mind that government research and development programs are not designed to produce product. They're designed to support government research and development programs into perpetuity. This applies to a lot of fields besides astronautics.

NASA will still be flailing around when the first private vehicle lands on the Moon.