I used to watch Sandy Denny and Nick Drake play alongside fine musicians who have survived them. These latter musicians have been performing all these years and maybe producing work that is sometimes patchy. They also look as old as I do.
It seems to be easier to forgive the ones that died young for any imperfections. It is probably also easier to sing certain songs when you appear to be young.
I suppose in some ways, if it the living musicians ego, that is responsible for these imperfections and uneven quality, then maybe it is because we no longer have to deal with the egos of the dead ones, that make us forgive them easier?