well, based upon your definition of tragic, then no, not all deaths would be tragic. If Joe Schmo dies, and I didn't know him then I would not be personally affected. I wouldn't shed a single tear over him. Same with celebrities.
However, to me, tragic doesn't imply personal grief. I can sympathize with the friends and family of the person who passed because I, like all people, understand what it's like to lose someone close to you. Beyond that, I also think that it is tasteless to not recognize this fact or worse, to joke or revel in someone's death. I hate to open this can of worms, but take Osama bin Laden. He is generally consider a bad person. He caused, either directly or indirectly, the death of countless numbers of people. However, even after he was killed, I didn't revel in his death. Sure, I was glad that he had been stopped, but death isn't something I would wish on anyone.