I believe we may be beating a dead horse here, and I will bow out of the debate after this (although I am certainly willing to read any response you may have). I don't believe there is any wrong or right where such personal needs are concerned. And no, of course the fact that those who would achieve some sort of closure by locating the body parts of their loved ones doesn't have to make sense to me.
As for the families of the MIA's from WWII, Korea, and Vietnam wanting to locate the remains of their loved ones, that is an entirely different situation from what occurred in the sky over Texas today.
Most of those families have no idea what happened to their loved ones. Some of them have even heard heartbreaking stories of POWs still being in the hands of their captors. It would seem to me that the not knowing would be maddening. On the other hand, as tragic a story as the horrible vapor trails of this morning tell, the astronaut's families have no questions regarding their loved one's final fate. Their mourning at least knows a starting point. The families of the men who never returned from war have to live with an eternal question mark, and their mourning is open-ended.