My understanding is that the effort wasn't extended with the understanding that the crew were doomed regardless of what information was gathered.
My view is that even if the crew were doomed, gathering additional information in advance of reentry would have allowed for a better understanding of circumstances, better post-disaster modeling of what went wrong and how the orbiter failed (both in the launch-time foam strike, and in the reentry heat-shield penetration and structural failure).
Whether or not to inform the crew is yet another decision. Astronauts are aware that theirs is a highly risky venture, though with a low sample size, the specific odds are somewhat uncertain, though on the order of 4:100 per human space flight. If you're going to go on a space mission, you'd better be prepared to die.
If NASA refrained from assessing strike damage on those grounds, I feel a grave error was committed.