timppu: Just to stress, it is irrelevant who the "original author/publisher/ip-holder" is. They could already be dead for all we know. All that matters is who the current publisher/IP rights holder is, that's the one getting most of the money.
So when you e.g. buy System Shock 2 from GOG (or Steam for that matter), probably no dime is going to that poor guy who designed the levels or sound effects for the game, or designed the ending credits. Just like I am not compensated at all anymore for some product I worked on developing for some company 10 years ago, even if it was still being sold. I've already switched jobs.
To be fair, you are paid a guaranteed wage on your endeavor.
Whoever is fronting money for the game (or software in general) is gambling on speculative income once the software is finished.
In essense, you take a smaller cut off the speculative pot in exchange for income security.
That being said, I'm more a fan of smaller endeavors where people churning out the product (code, art, design, etc) are the ones directly benefiting. I do agree that in the current scheme of things, the ones footing the money, but otherwise not contributing are an unfortunate necessary dead weight. It's gambling, it's not work.
I find the notion of minimum guaranteed income intriguing as it would cut out a lot of the private money many innovators must rely on to make a living while they work on their product.