Why do we never see a sign announcing a "grand closing"? It is probably because the closing down of a store is often not a celebratory event. Stores usually go out of business as a result of some unpleasant event; for example, when they are losing money, or when the owner dies or retires and nobody takes over. Who is to celebrate anything like that other than a competitor?
If it turned out that a giant asteroid was going to smash into earth and pulverize it into smithereens late tomorrow afternoon, that would certainly be the end of a significant era in the history of the solar system, if not of the universe. How would we then spend our last day of existence? We could sit around and fret over the luckless collective fate of humanity. But I think it would make more sense if we instead had one grand closing celebration and party like there was no tomorrow.