So what you're saying is that you think George R R Martin should not see a dime of revenue from the hit TV series made off of his books? Because Game of Thrones came out 20 years after the first book was published.
Second of all, even if you were correct, that would only apply to the first book, not the subsequent ones, which were spread out across 1999-2011 (indeed, A Dance with Dragons came out the same year as the TV series premiered).
So perhaps you'd like to pick a different copyright maximalist strawman?
Saying it's all theft entirely misses the point.
There is if it's taken without license when it would otherwise be restricted...
Looking past that specific word choice, there's an implication here that only the author would have an unbiased opinion on it. I'd argue that they're just as likely to have a bias that would cause them to argue for a policy that is unnecessarily onerous because by the same logic, they're not the ones who would be missing or on anything from it.
The vast majority of works make the vast majority of their money during that time frame. Indeed, for some works (like software), it's still probably much too long!
Citing a few wildly extreme outliers as evidence that we should stick with anything remotely resembling the current scheme a) is either disingenuous or betrays a deep misunderstanding of statistics, and b) can only work based on an appeal to emotion derived from growing up under the current scheme and seeing a creator's work as indelibly theirs forever, rather than something that should, once they have been allowed to make a living from it for a reasonable time, become the collective property of all humanity.
I find it highly probable that the negotiation for the rights to adapt for the screen included contractual agreements for him to do so to prevent them from hiring someone cheaper who would screw with his intended vision. He had leverage to ensure this outcome. They didn’t pay him a great deal more than they could have paid some unknown name because they are nice and friendly.