I'm inclined to agree. There's this tendency to take a "first = best" approach to creators. Just because someone created a character for Marvel or DC and that character has since generated billions in revenue, the assumption is that first creator handed Marvel/DC a billion dollar property. But the truth is often that these characters only become as valuable as they are thanks to the work of many, many other creators down the line - often not even in the same medium. Superman wouldn't be what he is today if we hadn't had Richard Donner and Christopher Reeves, as an example. So why is it anymore moral for Ditko's children to profit off the work of all the other Spider-Man creators than it is for Disney to profit off their work? What is, say, Mark Bagley owed for Spider-Man's total popularity? Creators definitely need to be more fairly compensated and credited - past and present - but handing the whole pie over to the first guy (or his heirs) just because he was first is problematic in its own way.