Then again, this was the NASA that thought it could ignore engineers and launch Challenger with frozen, leaky SRBs.
Since the same engineers had been telling them for five years that it was safe to launch with leaky SRB's (A part that's usually left out of the tale and most people are unaware of*) - I think NASA was more than justified in being a little skeptical of their last minute change in heart that they offered no justification more.
* That's why NASA was able to trot out a revised joint design so fast after the accident. The joint was a known problem and even though it was considered "safe" to continue flying, NASA and Morton-Thiokol were already working on a solution. (That the kludge that was the first flown joint design should never have entered service in the first place is another story.)