Eg. When some one day people only talk the good things.
Many legends of music or actor are that becuase they died
Aside from celebrities (which I can't explain) I don't think that most people idolize the dead - I think that they're in awe of them. Speaking for myself, I don't rate one person's history more significant than another - but it's humbling when I start complaining about stuff to look back at what our ancestors had to contend with. It doesn't minimize what I am going through at the time but it does help to put things in perspective. I don't admire my struggles faced with all of these wonderful technologies and advances in health care - but the fact that decades ago my ancestors came through all of their hardships to make my life possible does leave me with a sense of awe.
I don't idolize the dead. I tend to say nice things about the dead unless they were some weird jackoff like POTUS. (Sorry. He isn't dead yet.) But people do strange things that get into TV shows. I saw the rerun again of how Michael Jackson's doctor got convicted for his death. It's all interesting but the real one that killed Michael Jackson was first and foremost - Michael Jackson.
It's really just another expression of the fact that what you can't have seems more attractive than what you can take for granted. Also, it's a change of perspective. When the person's not around to get on your last nerve, it's easier to remember their kindness, dependability, generosity, etc. Also, you're far more aware that those things are now unavailable to you. We value what is rare. And what's rarer than the ephemeral memories of things we maybe didn't give proper appreciation and respect to when we had them?
I am not a member of those that idolize death. Not a clue as to why some place the absence of life in such high regards.