Monday was the day of appreciating David Bowie on my Facebook feed. That’s the way it is when people die; until that moment, you can, if you’re inclined to, say their best work is behind them, they were never that great anyway, etc etc. Afterwards, for a while at least, it’s pure appreciation, love, honor.
Why do we do it that way? It seems totally backwards. For my own part, I want everyone to appreciate me and tell me I’m great right now, while I can enjoy it. And if you think my work is overrated and anyway I’m kind of a jerk? After I’m dead would be an awesome time to bring that up. You have my permission, go for it.
Quomodocumque 
“We assume a special attitude towards the dead, something almost like admiration for one who has accomplished a very difficult feat. We suspend criticism of him, overlooking whatever wrongs he may have done, and issue the command, *De mortuis nil nice bene*: we act as if we were justified in singing his praises at the funeral oration, and inscribe only what is to his advantage on the tombstone. This consideration for the dead, which he really no longer needs, is more important to us than the truth, and, to most of us, certainly, it is more important than consideration for the living.” Freud, in _Thoughts for the Times on War and Death_ (1915), quoted in https://en.wikipedia.org/wiki/De_mortuis_nil_nisi_bonum
Fourier Analysis
No one who exists
Ever ceases to exist.
It’s just one’s vision —
Temporarily obscured.
— 2011 Dec 30
My answer (with no disrespect to Freud): Death in the public eye is a funny thing. It can restore the order, cutting down or making common those who saw far too much veneration or forgiveness while alive (think e.g. of Thatcher, who even had her own biopic while alive), or (as in the case of Bowie) making a legend of someone who was taken for granted.
I know that Bowie received acclaim throughout his career, even in his dry, drugged-out later years (before 2000), but I also think that his cultural influence and work as an “artist” were easy to overlook while he was alive. First of all, he kept his private life very private, hence the surprise of his death. Most of us took for granted the near-constant stream of creative fruits he produced over the course of six (!) decades, many of which became embedded in pop culture and taken for granted as they became cliché — an ironic sign of his vast influence on popular culture. This I believe is another reason he was taken for granted. A more direct reason is that he was (in the eyes of many) nothing more than a flashy rock star using superficial tricks and trends to sell records — certainly not an artist or a writer/commentator or a “renaissance man” (as he liked to call himself). His death, which brought forward legions of fans transcending generation, culture and class to express their genuine grief (and to acknowledge his influence), suggest that we should have perhaps thought of him more as that artist, writer/commentator, and renaissance man than we did.
Anyhow, to answer what I think is you your hypothetical question — it would be a lot more fun to have the veneration during one’s lifetime, I agree!
JSE: you’ve still got a lot of great things to do ahead of you, so don’t die for a long time.