On Dead Artists

I’ve been thinking about why artists are listened to once they die, specifically due to the lines in the song immortal by j. cole:

To die a young legend or live a long life unfulfilled? 'Cause you wanna change the world but while alive you never will 'Cause they only feel you after you gone, or I've been told And now I'm caught between bein' heard and gettin' old

I think one big aspect of it is a dead person doesn’t have interest in profit, or pushing any sort of agenda for personal gain; to me that makes what they say pure, and unadulterated by greed.