There's been a lot of kerfuffle in the press recently about the rights of comics creators over their, well, creations. We've had fights over Superman rights, Starlin annoyed about Thanos, Before Watchmen, various writers quitting DC and so on and so on... Indeed, it doesn't seem that a day goes by without someone else being rather annoyed that their not receiving their due (ie money) for their work.
The problem is that every single person has been paid exactly what their contract stated. Some of the contracts were a bit crappy, but the creators signed anyway.
While it would seem a good idea to pay Kirby (or his estate) a load of money for the work he did, paying out retrospectively like this throws up a thousand problems.
The main one is how much do you pay? Say DC & Marvel were suddenly feeling very generous and decided to give Kirby et al some money for the use of their character. Would a couple of $ do? How about $100? What about writers who only created a minor character? And the artists, surely they deserve something to? What about reinventions of characters? Drax the Destroyer, or example was created by Friedrich & Starlin but then had a drastic makeover during Marvel's Annihilation event. Starlin created Thanos, but was heavily influenced by New Gods so should we give Kirby a little something too regarding that character?
Storytelling will suffer. Say you now have to pay Bendis some money every time Maria Hill appears. The Marvel editorial staff will almost certainly demand that she no longer be written into stories. And if Bendis got a percentage from her appearing in the Avengers movie, then suddenly she'd be replaced with a very similar character, yet with enough difference so payment wouldn't be needed.
All of the characters created for DC & Marvel were 'work for hire', which is the main reason why the creators don't get paid anything beyond the wage they were paid at the time. The Big Two own the characters & everything else the creators did at the time.
...which makes it all very similar to every other job on the planet. If I go and work for a pharmaceutical company and help create a super drug to eliminate cancer, I wouldn't get a cut of the inevitable billions of dollars that that drug would make. I'd get paid my salary and that's it.
These days things are a little more improved. There are numerous creator-owned comics being published these days. If you work for DC & Marvel then everything you create belongs to them. Sounds bad, but then you do get to play around with a pool of characters which includes Superman, Iron Man etc.
And these days everyone is much more wary of the details before signing a contract.
This doesn't help the old guys, though. They still only received what they were paid at the time, back before anyone imagined $billion movies would result from their work. I do not think they will ever get anything more, it's just too much muddy water to sort out who deserves what. Time to learn from the past and ensure things are better for the future.