Hm, also at 10 years out how likely is the author to be able to convince someone to do a TV adaptation, knowing that by the time they're done someone else will be able to release their own versions (sans royalty even)?
Apparently the TV series Game of Thrones cost just under $600m to produce[1], and George R. R. Martin earnt something like $100m from royalties as its original author[2]. Although access to the author for advice and publicity must be valuable, that is nonetheless a very large proportion of the profits that I'm sure many studios would rather not have to share!
Many things are only popular for a relatively short period of time. If someone wants to wait until the copyright period is over to do an adaptation, the source material may no longer be that popular, and the adaptation, even without having paid a single royalty, will be unprofitable.
Ok but you’re gonna have a hard time convincing me that (morally) HBO should have been able to make game of thrones without cutting a check to the guy who created it
What about the lord of the rings movies? Tolkien didn't get paid from that, his heirs did.
What about Shakespeare.
What about the Brothers Grimm. Should Disnay have to pay for those fairy tales?
In the end every creative work stands on the shoulders of giants. We should reward creators for contributing to our culture but this notion that they should be able to own their creations way past when they become popular is absurd.
I'm not saying it'd be good for HBO to do that, only that they could. Regardless of whether or not they should, edge cases like GoT's success should not control the outcome for everyone and everything else.
[1]: https://movies.stackexchange.com/a/100996
[2]: https://www.dailymail.co.uk/tvshowbiz/article-6182197