When I think about it generously, I imagine that people who advocate for the enduring importance of such artists are, at heart, in mourning that their formative experiences will be shared by a decreasing portion of each ensuing generation.
They're fans! They want to geek out with other fans about Ender's Game, Repent Harlequin, Harry effin' Potter! And their disappointment with the situation translates to disappointment with the next generation of fandom for not finding joy where they did.