Well, in a story sense, such deaths serve different purposes. In a mystery, which IC was, however incoherent, you have to start out with the death of a major character. In a big comics "event," inevitably they have to throw something down like that(Orion dying at the start of FC, Earth-3 at the start of COIE, the Freedom Fighters at the start of InfC)because in order to whip up interest in an event you have to give a sense of, "My god, if they're willing to do that what ELSE might they do?" The deaths of characters you don't know well or care much about are different. They are there to show the seriousness of a threat. In the DCU, in the first few issues of an event, the characters who die generally bridge both categories. For instance, I don't care about the Hawks, but I still found their deaths at the start of BN a bit freaky.
Satisfyingly so, mind. I was so sick of them whining about their reincarnatory luvvv. I just wish the spear had gone through Carter first, because it was just as fridgy as the similar impalement between the tits of Dee Tyler, which I found kind of...ick. And not in the way I was supposed to.