Why?
Because that's the only way to protect America from those librul tree-hugging hippies in Washington DC who are letting America's guard down against the evil ones. We can't let our guard down because it is sure to result in another terrorist attack on American soil, which is bad, so therefore Osama needs to attack us like he did on 9/11 so that we'll wake up and not ever be attacked again like we were on 9/11.
But in all seriousness, it says something about the depravity of the right wing media when Americans getting killed is small price to pay… so long as it gives them a chance to crow about how terrible at governing liberals are.
Sigh. Priorities, you know.