>It's also notable that when Columbia disintegrated upon re-entry in 2003 the media and public at large didn't seem to pay it much attention at all (or at least I don't remember it being such a big deal).
It certainly was broadcast live -- every major TV news organization in the US broadcast the re-entry. Of course Columbia was very high altitude when it broke apart and the cameras (fortunately in my opinion) couldn't get very close-in shots.
There's a point to be made that people were more prepared for a possible disaster given the reports of damage to the shuttle that the crew provided days ahead, compared to the absolute surprise and shock at Challenger, and the horrifyingly clear camera footage provided at a lower altitude.
Probably because it wasn't broadcast live.