One of the reasons why there should be no renaming of the clock is that the name best encapsulates and represents the ideas and implications alluded to by the clock. The clock is a graphic representation of how close the human species is to extinction or some form of global catastrophe, also known as "doomsday". By including the term "doom" within the title, any inquiring person is immediately made aware of the gravitas and seriousness of the subject that is manifest within the clock. Changing the name would remove this immediate awareness, and diminish the seriousness of the possibility of human extinction.
I'm not sure which Clock of Doom this refers to. If it's the Tsunami clock in Hilo, I don't think so, since it's a public memorial meant to mark the time that the disaster occurred. If it's the Goosebumps book, I still don't think so, since it's not disrespectful of the victims, but tolls in their honor.
If the victims met their demise as the clock tolls , it reminds people of the sacrifices made in history . Great honor is bestowed upon the future generations that hear the stories of past heroics. Many others made the ultimate sacrifice and get no recognition or tribute payed in their honor.
While I don't disagree that Clock of Doom is a name which is better suited to that of a summer action blockbuster, I think at this point it is too late to change the title in people's minds. It is better that those souls are remembered than forgotten in confusion.