I agree with Amos and Saul both. I would also say, this doesn't seem to be a peculiarly American syndrome, as we also witnessed an over the top hysteria with the death of Princess Diana too. The media propaganda campaigns to heroicize those who die spectacular deaths, not only desensitizes us to the deaths of truly extraordinary people who have done truly extraordinary things (like the astronauts), but it also creates this bizarre series of public rituals of mourning for either the celebrity (in Diana's case, for instance) or the celebritized everyman (as in the 9/11 attacks), who becomes famous/infamous in death by the mere fact of it.
I don't know what the answer is, because I believe this is being driven mostly by the unprecedented amount of media coverage these deaths now receive. But while the media, especially in circumstances like the 9/11 attacks or Princess Diana's death, for the most part fuels and feeds the frenzy through it's propagandizing, politicians and government bureaucrats are also complicit in the propagandizing about the events when it has a perceived "national interest" they want to exploit to either their ideological or partisan advantage.
The unhealthiest aspects of this recent phenomenon, IMO, are the ways that certain people who have died, or who have loved ones who have died in the spectacular event, that don't fit the propaganda mold that the media and government are interested in perpetuating, can be demonized and marginalized, as happens all the time with husbands and fathers who become widowers when their wives are killed, or people/families who have associations with groups or events that don't fit the mold--political dissenters, people with a criminal history, people from a specific cultural, ethnic, religious, gender, etc background.
Another unhealthy aspect of this phenomenon are the unspoken taboos that get established surrounding the deceased and/or the event. These are either topics which get automatically stifled, or the venting of authentic grief, which includes a tremendous amount of anger. The media/government propagandizers rarely allow the use of footage of an angry person speaking their mind or venting their anger. This is probably the most damaging effect of the media coverage on people who are grieving on a personal level.
But there are now so many ways that people who just want to discuss their reactions, their questions, etc. about the events get shouted down in the wake of these things, I shudder to think what sort of generation we are raising up. It is our peers who police and forbid the open and frank discussion of these events in public forums such as this. It is in public forums where, in my experience, the policing of discussions is way out of proportion to the reality of the event in people's lives.
For example, in the US with 9/11, the government didn't have to set this new standard of repression and suppression of discussion and debate, because citizens and the media were already silencing the discussions that need to take place in a healthy society. That standard demands that people follow and swallow unquestioningly and uncritically, the mainstream propaganda line about what is and isn't appropriate to discuss in the wake of tragic events.
We in the US know what a damaging effect this new "public grieving" standard has had in the arena of public debate, especially in the media. It has been very difficult to recover from the excesses foisted upon us, especially when the issues that need debating stem from the over the top, reactionary steps taken by US politicians in the wake of 9/11, ie the passage of the US Patriot Act just weeks after the event.
It doesn't seem to be getting any better, does it?