Morally, should we prefer never to have existed?

We can morally compare possible alternative states of affairs, judging that various actual historical occurrences were bad, overall-the Holocaust, World War I, and slavery, for example. We should prefer that such events had not occurred, and regret that they had occurred. But the vast majority of people who now exist would not have existed had it not been for those historical events. A package deal is involved here: those events, together with oneself; or, the absence of the historical calamity, and the absence of oneself. So, all considered, ought one to prefer never to have existed, and to regret that one exists? Not in itself, of course, but as part of the conjunction? There seems to be a strong case for saying that morally one must wish and prefer that certain historical events had not occurred, even if that would have meant that one would never have existed. One ought to regret, all considered, that the aggregate state of affairs that includes one's existence is the one that materialized. After setting out this idea, I explore arguments against it, and attempt to reach a conclusion.